Hackerspace Bamberg - Backspace - Benutzerbeiträge [de]

HPCLJCP1510Repair

2015-09-20T18:22:20Z

Omicron:

{{Infobox Projekt
|name = HP CP1515n Color Calibration
|kategorie = Sonstiges
|status = stable
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = Fix Color Calibration of HP CP 1515n Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.0
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration (> 3 times)
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==

===Common===
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)

===Part 1: Trimmer===
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example: [[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise. For me, 90 degrees worked. However, the calibration seems to be quite sensitive to the exact position. Hence you have do some trial-and-error here. Example: [[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* Done (or try another trimmer position)
* If no trimmer position works, see long version

===Part 2: Springs===
* Remove one spring on each side of the ITB board. The following picture shows one of them in assembled state: 
[[File:Feder-eingebaut.jpg|400px]]
* The springs are only fixed on one end. The other end (the left end in the above picture) can simply be levered out using a big screwdriver.
* Afterwards, use two pairs of pliers for stretching the springs. This is done for the purpose of increasing the spring stiffness.
* It may be sensible to turn the pliers while stretching the spring for preventing an increase or decrease of the diameter of the spring.
* Afterwards reassemble the springs. This may be a little bit tricky and took me some minutes: I used two screwdrivers: One for tensioning the spring and putting it into the right place and another smaller screwdriver for stripping the spring from the first screwdriver - while pulling the first screwdriver out and leaving the spring in its place.

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
** The left cover for your own safety, because the high voltage components are located beneath it
* But (as always) be careful not to touch any live parts when the printer is connected to power!
* Instead of stretching the springs, you can of course replace them by a new one. However, it must be replaced by a spring with the appropriate length, stiffness and diameter, which most people (including myself) do not have at hand.

=Long Version=

Note that, if nothing else is mentioned, after each change I started calibration (at least, but usually only) twice.

Unfortunately, the short version worked only once. When I changed VR1 (see above), I also tightened the screws of the ITB. Hence there was a chance, that not the change of the trimmer led to success but the tightening of the screws. Hence, I changed back the trimmer to its original position and reassembled the printer. Then, as expected, the calibration failed again. Now I changed again the trimmer position as mentioned above and again reassembled the printer. Unfortunately, it did not work this time: Even after 3 calibrations the "L-lines" in the diagnostic page crossed each other.

Because of the above experience, I then supected a mechanical problem. Hence, I tightened the screws again. This time I used a special torque screwdriver and tightened all screws of the ITB module (which I could reach) with 1 Nm. Unfortunately, this did not help either.

My next attempt consisted of 4 things (I was quite in despair):
* I temporarily dismounted the front top part of the ITB and remounted it afterwards without doing any real change.
* I dismounted the two coil springs which seem to tighten the belt and stretched them with two pairs of pliers - for the purpose of increasing the spring stiffness (in a very amateurish way)
* I again turned all 3 trimmers in the exact position where the calibration initially worked
* I dismounted the 2 PCBs and removed the plastic covers covering the component side and cleaned them (for details see below)

After reassembling everything again, it worked again.

Now I again wanted to know, which change was the successful one (i. e. was it the cleaning of the PCB or some mechanical change), I turned the trimmer back to its original position. Now the calibration failed again. But after carefully turning the trimmer again into its known-working position, calibation was successful again.

Finally, I did some sensitivity analysis of the calibation working or not for various trimmer positions. During this analysis, at some point it did not work again. I then only increased the spring stiffness (again) without changing anything (apart from the "good" VR1 position). Afterwards, it worked again.

Then I inspected the mechanism which tightens the belt a little bit more carefully. From the beginning on, I noticed two rather loose plastic parts near the springs, which function I could not identify. After having reassembled the springs I noticed that they have to do with the tightening mechanism. The two plastic parts are levers to relax and tighten the ITB. However, I did not found any information about this feature in any document - neither the printer manual nor the service manual! Additionally, this tightening mechanism can be accessed even if the printer is fully mounted - with only the front door open (TODO: pictures!). Hence, it may have been enough to relax and re-tighten the ITB after re-assembling the printer instead of having to increase the spring stiffness at all! The re-tightening might increase the fit of the ITB assembly inside the printer.

Hence the original problem seems to have 2 causes:
* The spring stiffness of the ITB springs or the correct fit of the ITB in reassembled state
* The position of VR1

Finally, I did some sensitivity analysis of successful calibration to the positions of the 3 trimmers - starting from the now hopefully well-reproducible good position of VR1.

As it turned out, I obviously initially hit the correct trimmer position of VR1 by chance: The trimmer position needs to be in a range of about +/- 5-10 degrees to be optimal, i. e. leading to a correct calibration.

HPCLJCP1510Repair

2015-09-20T18:20:33Z

Omicron: /* Long Version */

{{Infobox Projekt
|name = HP CP1515n Color Calibration
|kategorie = Sonstiges
|status = unstable
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = Fix Color Calibration of HP CP 1515n Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.0
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration (> 3 times)
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==

===Common===
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)

===Part 1: Trimmer===
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example: [[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise. For me, 90 degrees worked. However, the calibration seems to be quite sensitive to the exact position. Hence you have do some trial-and-error here. Example: [[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* Done (or try another trimmer position)
* If no trimmer position works, see long version

===Part 2: Springs===
* Remove one spring on each side of the ITB board. The following picture shows one of them in assembled state: 
[[File:Feder-eingebaut.jpg|400px]]
* The springs are only fixed on one end. The other end (the left end in the above picture) can simply be levered out using a big screwdriver.
* Afterwards, use two pairs of pliers for stretching the springs. This is done for the purpose of increasing the spring stiffness.
* It may be sensible to turn the pliers while stretching the spring for preventing an increase or decrease of the diameter of the spring.
* Afterwards reassemble the springs. This may be a little bit tricky and took me some minutes: I used two screwdrivers: One for tensioning the spring and putting it into the right place and another smaller screwdriver for stripping the spring from the first screwdriver - while pulling the first screwdriver out and leaving the spring in its place.

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
** The left cover for your own safety, because the high voltage components are located beneath it
* But (as always) be careful not to touch any live parts when the printer is connected to power!
* Instead of stretching the springs, you can of course replace them by a new one. However, it must be replaced by a spring with the appropriate length, stiffness and diameter, which most people (including myself) do not have at hand.

=Long Version=

Note that, if nothing else is mentioned, after each change I started calibration (at least, but usually only) twice.

Unfortunately, the short version worked only once. When I changed VR1 (see above), I also tightened the screws of the ITB. Hence there was a chance, that not the change of the trimmer led to success but the tightening of the screws. Hence, I changed back the trimmer to its original position and reassembled the printer. Then, as expected, the calibration failed again. Now I changed again the trimmer position as mentioned above and again reassembled the printer. Unfortunately, it did not work this time: Even after 3 calibrations the "L-lines" in the diagnostic page crossed each other.

Because of the above experience, I then supected a mechanical problem. Hence, I tightened the screws again. This time I used a special torque screwdriver and tightened all screws of the ITB module (which I could reach) with 1 Nm. Unfortunately, this did not help either.

My next attempt consisted of 4 things (I was quite in despair):
* I temporarily dismounted the front top part of the ITB and remounted it afterwards without doing any real change.
* I dismounted the two coil springs which seem to tighten the belt and stretched them with two pairs of pliers - for the purpose of increasing the spring stiffness (in a very amateurish way)
* I again turned all 3 trimmers in the exact position where the calibration initially worked
* I dismounted the 2 PCBs and removed the plastic covers covering the component side and cleaned them (for details see below)

After reassembling everything again, it worked again.

Now I again wanted to know, which change was the successful one (i. e. was it the cleaning of the PCB or some mechanical change), I turned the trimmer back to its original position. Now the calibration failed again. But after carefully turning the trimmer again into its known-working position, calibation was successful again.

Finally, I did some sensitivity analysis of the calibation working or not for various trimmer positions. During this analysis, at some point it did not work again. I then only increased the spring stiffness (again) without changing anything (apart from the "good" VR1 position). Afterwards, it worked again.

Then I inspected the mechanism which tightens the belt a little bit more carefully. From the beginning on, I noticed two rather loose plastic parts near the springs, which function I could not identify. After having reassembled the springs I noticed that they have to do with the tightening mechanism. The two plastic parts are levers to relax and tighten the ITB. However, I did not found any information about this feature in any document - neither the printer manual nor the service manual! Additionally, this tightening mechanism can be accessed even if the printer is fully mounted - with only the front door open (TODO: pictures!). Hence, it may have been enough to relax and re-tighten the ITB after re-assembling the printer instead of having to increase the spring stiffness at all! The re-tightening might increase the fit of the ITB assembly inside the printer.

Hence the original problem seems to have 2 causes:
* The spring stiffness of the ITB springs or the correct fit of the ITB in reassembled state
* The position of VR1

Finally, I did some sensitivity analysis of successful calibration to the positions of the 3 trimmers - starting from the now hopefully well-reproducible good position of VR1.

As it turned out, I obviously initially hit the correct trimmer position of VR1 by chance: The trimmer position needs to be in a range of about +/- 5-10 degrees to be optimal, i. e. leading to a correct calibration.

HPCLJCP1510Repair

2015-09-20T18:18:32Z

Omicron: /* Notes */

{{Infobox Projekt
|name = HP CP1515n Color Calibration
|kategorie = Sonstiges
|status = unstable
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = Fix Color Calibration of HP CP 1515n Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.0
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration (> 3 times)
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==

===Common===
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)

===Part 1: Trimmer===
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example: [[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise. For me, 90 degrees worked. However, the calibration seems to be quite sensitive to the exact position. Hence you have do some trial-and-error here. Example: [[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* Done (or try another trimmer position)
* If no trimmer position works, see long version

===Part 2: Springs===
* Remove one spring on each side of the ITB board. The following picture shows one of them in assembled state: 
[[File:Feder-eingebaut.jpg|400px]]
* The springs are only fixed on one end. The other end (the left end in the above picture) can simply be levered out using a big screwdriver.
* Afterwards, use two pairs of pliers for stretching the springs. This is done for the purpose of increasing the spring stiffness.
* It may be sensible to turn the pliers while stretching the spring for preventing an increase or decrease of the diameter of the spring.
* Afterwards reassemble the springs. This may be a little bit tricky and took me some minutes: I used two screwdrivers: One for tensioning the spring and putting it into the right place and another smaller screwdriver for stripping the spring from the first screwdriver - while pulling the first screwdriver out and leaving the spring in its place.

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
** The left cover for your own safety, because the high voltage components are located beneath it
* But (as always) be careful not to touch any live parts when the printer is connected to power!
* Instead of stretching the springs, you can of course replace them by a new one. However, it must be replaced by a spring with the appropriate length, stiffness and diameter, which most people (including myself) do not have at hand.

=Long Version=

Note that, if nothing else is mentioned, after each change I started calibration (at least, but usually only) twice.

Unfortunately, the short version worked only once. When I changed VR1 (see above), I also tightened the screws of the ITB. Hence there was a chance, that not the change of the trimmer led to success but the tightening of the screws. Hence, I changed back the trimmer to its original position and reassembled the printer. Then, as expected, the calibration failed again. Now I changed again the trimmer position as mentioned above and again reassembled the printer. Unfortunately, it did not work this time: Even after 3 calibrations the "L-lines" in the diagnostic page crossed each other.

Because of the above experience, I then supected a mechanical problem. Hence, I tightened the screws again. This time I used a special torque screwdriver and tightened all screws of the ITB module (which I could reach) with 1 Nm. Unfortunately, this did not help either.

My next attempt consisted of 4 things (I was quite in despair):
* I temporarily dismounted the front top part of the ITB (see TODO) and remounted it afterwards without doing any real change.
* I dismounted the two coil springs which seem to tighten the belt and stretched them with two pairs of pliers - for the purpose of increasing the spring stiffness (in a very amateurish way)
* I again turned all 3 trimmers in the exact position where the calibration initially worked
* I dismounted the 2 PCBs and removed the plastic covers covering the component side and cleaned them (for details see below)

After reassembling everything again, it worked again.

Now I again wanted to know, which change was the successful one (i. e. was it the cleaning of the PCB or some mechanical change), I turned the trimmer back to its original position. Now the calibration failed again. But after carefully turning the trimmer again into its known-working position, calibation was successful again.

Finally, I did some sensitivity analysis of the calibation working or not for various trimmer positions. During this analysis, at some point it did not work again. I then only increased the spring stiffness (again) without changing anything (apart from the "good" VR1 position). Afterwards, it worked again.

Then I inspected the mechanism which tightens the belt a little bit more carefully. From the beginning on, I noticed two rather loose plastic parts near the springs, which function I could not identify. After having reassembled the springs I noticed that they have to do with the tightening mechanism. The two plastic parts are levers to relax and tighten the ITB. However, I did not found any information about this feature in any document - neither the printer manual nor the service manual! Additionally, this tightening mechanism can be accessed even if the printer is fully mounted - with only the front door open (TODO: pictures!). Hence, it may have been enough to relax and re-tighten the ITB after re-assembling the printer instead of having to increase the spring stiffness at all! The re-tightening might increase the fit of the ITB assembly inside the printer.

Hence the original problem seems to have 2 causes:
* The spring stiffness of the ITB springs or the correct fit of the ITB in reassembled state
* The position of VR1

Finally, I did some sensitivity analysis of successful calibration to the positions of the 3 trimmers - starting from the now hopefully well-reproducible good position of VR1.

TODO:
As it turned out, I obviouly initially hit the correct trimmer position of VR1 by chance: The trimmer position must be in a range of about +/- 5-10 degrees to be optimal, i. e. leading to a correct calibration!

HPCLJCP1510Repair

2015-09-20T18:14:52Z

Omicron: /* Part 2: Springs */

{{Infobox Projekt
|name = HP CP1515n Color Calibration
|kategorie = Sonstiges
|status = unstable
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = Fix Color Calibration of HP CP 1515n Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.0
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration (> 3 times)
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==

===Common===
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)

===Part 1: Trimmer===
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example: [[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise. For me, 90 degrees worked. However, the calibration seems to be quite sensitive to the exact position. Hence you have do some trial-and-error here. Example: [[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* Done (or try another trimmer position)
* If no trimmer position works, see long version

===Part 2: Springs===
* Remove one spring on each side of the ITB board. The following picture shows one of them in assembled state: 
[[File:Feder-eingebaut.jpg|400px]]
* The springs are only fixed on one end. The other end (the left end in the above picture) can simply be levered out using a big screwdriver.
* Afterwards, use two pairs of pliers for stretching the springs. This is done for the purpose of increasing the spring stiffness.
* It may be sensible to turn the pliers while stretching the spring for preventing an increase or decrease of the diameter of the spring.
* Afterwards reassemble the springs. This may be a little bit tricky and took me some minutes: I used two screwdrivers: One for tensioning the spring and putting it into the right place and another smaller screwdriver for stripping the spring from the first screwdriver - while pulling the first screwdriver out and leaving the spring in its place.

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
** The left cover for your own safety, because the high voltage components are located beneath it
* But (as always) be careful not to touch any live parts when the printer is connected to power!

=Long Version=

Note that, if nothing else is mentioned, after each change I started calibration (at least, but usually only) twice.

Unfortunately, the short version worked only once. When I changed VR1 (see above), I also tightened the screws of the ITB. Hence there was a chance, that not the change of the trimmer led to success but the tightening of the screws. Hence, I changed back the trimmer to its original position and reassembled the printer. Then, as expected, the calibration failed again. Now I changed again the trimmer position as mentioned above and again reassembled the printer. Unfortunately, it did not work this time: Even after 3 calibrations the "L-lines" in the diagnostic page crossed each other.

Because of the above experience, I then supected a mechanical problem. Hence, I tightened the screws again. This time I used a special torque screwdriver and tightened all screws of the ITB module (which I could reach) with 1 Nm. Unfortunately, this did not help either.

My next attempt consisted of 4 things (I was quite in despair):
* I temporarily dismounted the front top part of the ITB (see TODO) and remounted it afterwards without doing any real change.
* I dismounted the two coil springs which seem to tighten the belt and stretched them with two pairs of pliers - for the purpose of increasing the spring stiffness (in a very amateurish way)
* I again turned all 3 trimmers in the exact position where the calibration initially worked
* I dismounted the 2 PCBs and removed the plastic covers covering the component side and cleaned them (for details see below)

After reassembling everything again, it worked again.

Now I again wanted to know, which change was the successful one (i. e. was it the cleaning of the PCB or some mechanical change), I turned the trimmer back to its original position. Now the calibration failed again. But after carefully turning the trimmer again into its known-working position, calibation was successful again.

Finally, I did some sensitivity analysis of the calibation working or not for various trimmer positions. During this analysis, at some point it did not work again. I then only increased the spring stiffness (again) without changing anything (apart from the "good" VR1 position). Afterwards, it worked again.

Then I inspected the mechanism which tightens the belt a little bit more carefully. From the beginning on, I noticed two rather loose plastic parts near the springs, which function I could not identify. After having reassembled the springs I noticed that they have to do with the tightening mechanism. The two plastic parts are levers to relax and tighten the ITB. However, I did not found any information about this feature in any document - neither the printer manual nor the service manual! Additionally, this tightening mechanism can be accessed even if the printer is fully mounted - with only the front door open (TODO: pictures!). Hence, it may have been enough to relax and re-tighten the ITB after re-assembling the printer instead of having to increase the spring stiffness at all! The re-tightening might increase the fit of the ITB assembly inside the printer.

Hence the original problem seems to have 2 causes:
* The spring stiffness of the ITB springs or the correct fit of the ITB in reassembled state
* The position of VR1

Finally, I did some sensitivity analysis of successful calibration to the positions of the 3 trimmers - starting from the now hopefully well-reproducible good position of VR1.

TODO:
As it turned out, I obviouly initially hit the correct trimmer position of VR1 by chance: The trimmer position must be in a range of about +/- 5-10 degrees to be optimal, i. e. leading to a correct calibration!

Datei:Feder-eingebaut.jpg

2015-09-20T17:58:44Z

Omicron:

HPCLJCP1510Repair

2015-09-20T17:57:56Z

Omicron: /* Solution */

{{Infobox Projekt
|name = HP CP1515n Color Calibration
|kategorie = Sonstiges
|status = unstable
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = Fix Color Calibration of HP CP 1515n Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.0
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration (> 3 times)
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==

===Common===
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)

===Part 1: Trimmer===
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example: [[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise. For me, 90 degrees worked. However, the calibration seems to be quite sensitive to the exact position. Hence you have do some trial-and-error here. Example: [[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* Done (or try another trimmer position)
* If no trimmer position works, see long version

===Part 2: Springs===
* Remove the 2 springs on the side of the ITB board. The following picture shows one of them in built-in state: 
[[File:Feder-eingebaut.jpg|400px]]

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
** The left cover for your own safety, because the high voltage components are located beneath it
* But (as always) be careful not to touch any live parts when the printer is connected to power!

=Long Version=

Note that, if nothing else is mentioned, after each change I started calibration (at least, but usually only) twice.

Unfortunately, the short version worked only once. When I changed VR1 (see above), I also tightened the screws of the ITB. Hence there was a chance, that not the change of the trimmer led to success but the tightening of the screws. Hence, I changed back the trimmer to its original position and reassembled the printer. Then, as expected, the calibration failed again. Now I changed again the trimmer position as mentioned above and again reassembled the printer. Unfortunately, it did not work this time: Even after 3 calibrations the "L-lines" in the diagnostic page crossed each other.

Because of the above experience, I then supected a mechanical problem. Hence, I tightened the screws again. This time I used a special torque screwdriver and tightened all screws of the ITB module (which I could reach) with 1 Nm. Unfortunately, this did not help either.

My next attempt consisted of 4 things (I was quite in despair):
* I temporarily dismounted the front top part of the ITB (see TODO) and remounted it afterwards without doing any real change.
* I dismounted the two coil springs which seem to tighten the belt and stretched them with two pairs of pliers - for the purpose of increasing the spring stiffness (in a very amateurish way)
* I again turned all 3 trimmers in the exact position where the calibration initially worked
* I dismounted the 2 PCBs and removed the plastic covers covering the component side and cleaned them (for details see below)

After reassembling everything again, it worked again.

Now I again wanted to know, which change was the successful one (i. e. was it the cleaning of the PCB or some mechanical change), I turned the trimmer back to its original position. Now the calibration failed again. But after carefully turning the trimmer again into its known-working position, calibation was successful again.

Finally, I did some sensitivity analysis of the calibation working or not for various trimmer positions. During this analysis, at some point it did not work again. I then only increased the spring stiffness (again) without changing anything (apart from the "good" VR1 position). Afterwards, it worked again.

Then I inspected the mechanism which tightens the belt a little bit more carefully. From the beginning on, I noticed two rather loose plastic parts near the springs, which function I could not identify. After having reassembled the springs I noticed that they have to do with the tightening mechanism. The two plastic parts are levers to relax and tighten the ITB. However, I did not found any information about this feature in any document - neither the printer manual nor the service manual! Additionally, this tightening mechanism can be accessed even if the printer is fully mounted - with only the front door open (TODO: pictures!). Hence, it may have been enough to relax and re-tighten the ITB after re-assembling the printer instead of having to increase the spring stiffness at all! The re-tightening might increase the fit of the ITB assembly inside the printer.

Hence the original problem seems to have 2 causes:
* The spring stiffness of the ITB springs or the correct fit of the ITB in reassembled state
* The position of VR1

Finally, I did some sensitivity analysis of successful calibration to the positions of the 3 trimmers - starting from the now hopefully well-reproducible good position of VR1.

TODO:
As it turned out, I obviouly initially hit the correct trimmer position of VR1 by chance: The trimmer position must be in a range of about +/- 5-10 degrees to be optimal, i. e. leading to a correct calibration!

HPCLJCP1510Repair

2015-08-08T21:10:19Z

Omicron: /* Long Version */

{{Infobox Projekt
|name = HP CP1515n Color Calibration
|kategorie = Sonstiges
|status = unstable
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = Fix Color Calibration of HP CP 1515n Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.0
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration (> 3 times)
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example: [[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise. For me, 90 degrees worked. However, the calibration seems to be quite sensitive to the exact position. Hence you have do some trial-and-error here. Example: [[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* Done (or try another trimmer position)
* If no trimmer position works, see long version

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
** The left cover for your own safety, because the high voltage components are located beneath it
* But (as always) be careful not to touch any live parts when the printer is connected to power!

=Long Version=

Note that, if nothing else is mentioned, after each change I started calibration (at least, but usually only) twice.

Unfortunately, the short version worked only once. When I changed VR1 (see above), I also tightened the screws of the ITB. Hence there was a chance, that not the change of the trimmer led to success but the tightening of the screws. Hence, I changed back the trimmer to its original position and reassembled the printer. Then, as expected, the calibration failed again. Now I changed again the trimmer position as mentioned above and again reassembled the printer. Unfortunately, it did not work this time: Even after 3 calibrations the "L-lines" in the diagnostic page crossed each other.

Because of the above experience, I then supected a mechanical problem. Hence, I tightened the screws again. This time I used a special torque screwdriver and tightened all screws of the ITB module (which I could reach) with 1 Nm. Unfortunately, this did not help either.

My next attempt consisted of 4 things (I was quite in despair):
* I temporarily dismounted the front top part of the ITB (see TODO) and remounted it afterwards without doing any real change.
* I dismounted the two coil springs which seem to tighten the belt and stretched them with two pairs of pliers - for the purpose of increasing the spring stiffness (in a very amateurish way)
* I again turned all 3 trimmers in the exact position where the calibration initially worked
* I dismounted the 2 PCBs and removed the plastic covers covering the component side and cleaned them (for details see below)

After reassembling everything again, it worked again.

Now I again wanted to know, which change was the successful one (i. e. was it the cleaning of the PCB or some mechanical change), I turned the trimmer back to its original position. Now the calibration failed again. But after carefully turning the trimmer again into its known-working position, calibation was successful again.

Finally, I did some sensitivity analysis of the calibation working or not for various trimmer positions. During this analysis, at some point it did not work again. I then only increased the spring stiffness (again) without changing anything (apart from the "good" VR1 position). Afterwards, it worked again.

Then I inspected the mechanism which tightens the belt a little bit more carefully. From the beginning on, I noticed two rather loose plastic parts near the springs, which function I could not identify. After having reassembled the springs I noticed that they have to do with the tightening mechanism. The two plastic parts are levers to relax and tighten the ITB. However, I did not found any information about this feature in any document - neither the printer manual nor the service manual! Additionally, this tightening mechanism can be accessed even if the printer is fully mounted - with only the front door open (TODO: pictures!). Hence, it may have been enough to relax and re-tighten the ITB after re-assembling the printer instead of having to increase the spring stiffness at all! The re-tightening might increase the fit of the ITB assembly inside the printer.

Hence the original problem seems to have 2 causes:
* The spring stiffness of the ITB springs or the correct fit of the ITB in reassembled state
* The position of VR1

Finally, I did some sensitivity analysis of successful calibration to the positions of the 3 trimmers - starting from the now hopefully well-reproducible good position of VR1.

TODO:
As it turned out, I obviouly initially hit the correct trimmer position of VR1 by chance: The trimmer position must be in a range of about +/- 5-10 degrees to be optimal, i. e. leading to a correct calibration!

HPCLJCP1510Repair

2015-08-08T20:46:48Z

Omicron: /* Solution */

HPCLJCP1510Repair

2015-08-08T19:47:52Z

Omicron:

HPCLJCP1510Repair

2015-08-08T19:45:56Z

Omicron:

{{Infobox Projekt
|name = HP CP1515n Color Calibration
|kategorie = Sonstiges
|status = experimentell
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = Fix Color Calibration of HP CP 1515n Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.0
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration (> 3 times)
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example: [[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise (for me, 90 degrees worked. However, the calibration seems to be quite sensitive to the exact position. Hence you have do some trial-and-error here. Example: [[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* Done (or try another trimmer position)
* If no trimmer position works, see long version

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
** The left cover for your own safety, because the high voltage components are located beneath it
* But (as always) be careful not to touch any live parts when the printer is connected to power!

=Long Version=

Note that, if nothing else is mentioned, after each change I started calibration (at least, but usually only) twice.

Unfortunately, the short version worked only once. When I changed VR1 (see above), I also tightened the screws of the ITB. Hence there was a chance, that not the change of the trimmer led to success but the tightening of the screws. Hence, I changed back the trimmer to its original position and reassembled the printer. Then, as expected, the calibration failed again. Now I changed again the trimmer position as mentioned above and again reassembled the printer. Unfortunately, it did not work this time: Even after 3 calibrations the "L-lines" in the diagnostic page crossed each other.

Because of the above experience, I then supected a mechanical problem. Hence, I tightened the screws again. This time I used a special torque screwdriver and tightened all screws of the ITB module (which I could reach) with 1 Nm. Unfortunately, this did not help either.

My next attempt consisted of 4 things (I was quite in despair):
* I temporarily dismounted the front top part of the ITB (see TODO) and remounted it afterwards without doing any real change.
* I dismounted the two coil springs which seem to tighten the belt and stretched them with two pairs of pliers - for the purpose of increasing the spring stiffness (in a very amateurish way)
* I again turned all 3 trimmers in the exact position where the calibration initially worked
* I dismounted the 2 PCBs and removed the plastic covers covering the component side and cleaned them (for details see below)

After reassembling everything again, it worked again.

Now I again wanted to know, which change was the successful one (i. e. was it the cleaning of the PCB or some mechanical change), I turned the trimmer back to its original position. Now the calibration failed again. But after carefully turning the trimmer again into its known-working position, calibation was successful again.

Finally, I did some sensitivity analysis of the calibation working or not for various trimmer positions. As it turned out, I obviouly initially hit the correct trimmer position of VR1 by chance: The trimmer position must be in a range of about +/- 5-10 degrees to be optimal, i. e. leading to a correct calibration!

HPCLJCP1510Repair

2015-08-03T21:39:41Z

Omicron: /* Notes */

{{Infobox Projekt
|name = HP CP1515n Color Calibration
|kategorie = Sonstiges
|status = in development
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = Fix Color Calibration of HP CP 1515n Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.0
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration (> 3 times)
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example: [[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise (for me, 90 degrees worked. However, the calibration seems to be quite sensitive to the exact position. Hence you have do some trial-and-error here. Example: [[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* Done (or try another trimmer position)
* If no trimmer position works, see long version

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
** The left cover for your own safety, because the high voltage components are located beneath it
* But (as always) be careful not to touch any live parts when the printer is connected to power!

=Long Version=

Note that, if nothing else is mentioned, after each change I started calibration (at least, but usually only) twice.

Unfortunately, the short version worked only once. When I changed VR1 (see above), I also tightened the screws of the ITB. Hence there was a chance, that not the change of the trimmer led to success but the tightening of the screws. Hence, I changed back the trimmer to its original position and reassembled the printer. Then, as expected, the calibration failed again. Now I changed again the trimmer position as mentioned above and again reassembled the printer. Unfortunately, it did not work this time: Even after 3 calibrations the "L-lines" in the diagnostic page crossed each other.

Because of the above experience, I then supected a mechanical problem. Hence, I tightened the screws again. This time I used a special torque screwdriver and tightened all screws of the ITB module (which I could reach) with 1 Nm. Unfortunately, this did not help either.

My next attempt consisted of 4 things (I was quite in despair):
* I temporarily dismounted the front top part of the ITB (see TODO) and remounted it afterwards without doing any real change.
* I dismounted the two coil springs which seem to tighten the belt and stretched them with two pairs of pliers - for the purpose of increasing the spring stiffness (in a very amateurish way)
* I again turned all 3 trimmers in the exact position where the calibration initially worked
* I dismounted the 2 PCBs and removed the plastic covers covering the component side and cleaned them (for details see below)

After reassembling everything again, it worked again.

Now I again wanted to know, which change was the successful one (i. e. was it the cleaning of the PCB or some mechanical change), I turned the trimmer back to its original position. Now the calibration failed again. But after carefully turning the trimmer again into its known-working position, calibation was successful again.

Finally, I did some sensitivity analysis of the calibation working or not for various trimmer positions. As it turned out, I obviouly initially hit the correct trimmer position of VR1 by chance: The trimmer position must be in a range of about +/- 5-10 degrees to be optimal, i. e. leading to a correct calibration!

HPCLJCP1510Repair

2015-08-03T21:38:14Z

Omicron: /* Solution */

{{Infobox Projekt
|name = HP CP1515n Color Calibration
|kategorie = Sonstiges
|status = in development
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = Fix Color Calibration of HP CP 1515n Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.0
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration (> 3 times)
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example: [[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise (for me, 90 degrees worked. However, the calibration seems to be quite sensitive to the exact position. Hence you have do some trial-and-error here. Example: [[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* Done (or try another trimmer position)
* If no trimmer position works, see long version

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
* But (as always) be careful not to touch any live parts when the printer is connected to power!

=Long Version=

Note that, if nothing else is mentioned, after each change I started calibration (at least, but usually only) twice.

Unfortunately, the short version worked only once. When I changed VR1 (see above), I also tightened the screws of the ITB. Hence there was a chance, that not the change of the trimmer led to success but the tightening of the screws. Hence, I changed back the trimmer to its original position and reassembled the printer. Then, as expected, the calibration failed again. Now I changed again the trimmer position as mentioned above and again reassembled the printer. Unfortunately, it did not work this time: Even after 3 calibrations the "L-lines" in the diagnostic page crossed each other.

Because of the above experience, I then supected a mechanical problem. Hence, I tightened the screws again. This time I used a special torque screwdriver and tightened all screws of the ITB module (which I could reach) with 1 Nm. Unfortunately, this did not help either.

My next attempt consisted of 4 things (I was quite in despair):
* I temporarily dismounted the front top part of the ITB (see TODO) and remounted it afterwards without doing any real change.
* I dismounted the two coil springs which seem to tighten the belt and stretched them with two pairs of pliers - for the purpose of increasing the spring stiffness (in a very amateurish way)
* I again turned all 3 trimmers in the exact position where the calibration initially worked
* I dismounted the 2 PCBs and removed the plastic covers covering the component side and cleaned them (for details see below)

After reassembling everything again, it worked again.

Now I again wanted to know, which change was the successful one (i. e. was it the cleaning of the PCB or some mechanical change), I turned the trimmer back to its original position. Now the calibration failed again. But after carefully turning the trimmer again into its known-working position, calibation was successful again.

Finally, I did some sensitivity analysis of the calibation working or not for various trimmer positions. As it turned out, I obviouly initially hit the correct trimmer position of VR1 by chance: The trimmer position must be in a range of about +/- 5-10 degrees to be optimal, i. e. leading to a correct calibration!

HPCLJCP1510Repair

2015-08-03T21:34:04Z

Omicron: /* Long Version */

{{Infobox Projekt
|name = HP CP1515n Color Calibration
|kategorie = Sonstiges
|status = in development
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = Fix Color Calibration of HP CP 1515n Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.0
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration (> 3 times)
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example: [[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise about 90 degrees (other angles could work, too: Try it out!). Example: [[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* Done (or further experiments needed - see notes)

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
* But (as always) be careful not to touch any live parts when the printer is connected to power!

=Long Version=

Note that, if nothing else is mentioned, after each change I started calibration (at least, but usually only) twice.

Unfortunately, the short version worked only once. When I changed VR1 (see above), I also tightened the screws of the ITB. Hence there was a chance, that not the change of the trimmer led to success but the tightening of the screws. Hence, I changed back the trimmer to its original position and reassembled the printer. Then, as expected, the calibration failed again. Now I changed again the trimmer position as mentioned above and again reassembled the printer. Unfortunately, it did not work this time: Even after 3 calibrations the "L-lines" in the diagnostic page crossed each other.

Because of the above experience, I then supected a mechanical problem. Hence, I tightened the screws again. This time I used a special torque screwdriver and tightened all screws of the ITB module (which I could reach) with 1 Nm. Unfortunately, this did not help either.

My next attempt consisted of 4 things (I was quite in despair):
* I temporarily dismounted the front top part of the ITB (see TODO) and remounted it afterwards without doing any real change.
* I dismounted the two coil springs which seem to tighten the belt and stretched them with two pairs of pliers - for the purpose of increasing the spring stiffness (in a very amateurish way)
* I again turned all 3 trimmers in the exact position where the calibration initially worked
* I dismounted the 2 PCBs and removed the plastic covers covering the component side and cleaned them (for details see below)

After reassembling everything again, it worked again.

Now I again wanted to know, which change was the successful one (i. e. was it the cleaning of the PCB or some mechanical change), I turned the trimmer back to its original position. Now the calibration failed again. But after carefully turning the trimmer again into its known-working position, calibation was successful again.

Finally, I did some sensitivity analysis of the calibation working or not for various trimmer positions. As it turned out, I obviouly initially hit the correct trimmer position of VR1 by chance: The trimmer position must be in a range of about +/- 5-10 degrees to be optimal, i. e. leading to a correct calibration!

Datei:VR1-Original.jpg

2015-07-25T23:54:49Z

Omicron: Omicron lud eine neue Version von Datei:VR1-Original.jpg hoch

Datei hochgeladen mit MsUpload

Datei:VR1-Changed-Good.jpg

2015-07-25T23:54:10Z

Omicron: Omicron lud eine neue Version von Datei:VR1-Changed-Good.jpg hoch

Datei hochgeladen mit MsUpload

HPCLJCP1510Repair

2015-07-25T23:11:31Z

Omicron:

HPCLJCP1510Repair

2015-07-25T23:09:39Z

Omicron:

HPCP1250Repair

2015-07-25T23:03:22Z

Omicron:

HPCP1250Repair

2015-07-25T22:58:31Z

Omicron: Die Seite wurde geleert.

HPCP1250Repair

2015-07-25T22:57:59Z

Omicron: Omicron verschob die Seite HPCP1250Repair nach HPCLJCP1510Repair: Modellnummer 1250 existiert nicht.

#WEITERLEITUNG [[HPCLJCP1510Repair]]

HPCLJCP1510Repair

2015-07-25T22:57:58Z

Omicron: Omicron verschob die Seite HPCP1250Repair nach HPCLJCP1510Repair: Modellnummer 1250 existiert nicht.

{{Infobox Projekt
|name = Fix HP LaserJet Calibration Problem
|kategorie = Sonstiges
|status = in development
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = How to fix calibration problem of HP LaserJet 1510 Series Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.5
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1510 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration done > 3 times
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==
* Print diagnostics page using the printer menu (for later comparison).
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB)
* Turn the ITB assembly upside down
* Find the two small PCBs where the wires end
* Take a photo of the positions of all 3 trimmer (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it). Example:
[[File:VR1-Original.jpg|200px]]
* Turn VR1 clockwise about 90 degrees (other angles could work, too: Try it out!). Example:
[[File:VR1-Changed-Good.jpg|200px]]
* Follow the instructions of the service manual for re-installing the ITB assembly
* Connect printer to power
* Start a color calibration
* Print diagnostics page and compare with diagnostics page before the fix
* done (or further experiments needed - see notes)

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
* But (as always) be careful not to touch any live parts when the printer is connected to power!

=Long Version=

This will (or may) be writen as soon as the author finds time and motivation...

HPCLJCP1510Repair

2015-07-25T22:56:40Z

Omicron:

Datei:VR1-Changed-Good.jpg

2015-07-25T22:47:41Z

Omicron: Datei hochgeladen mit MsUpload

Datei hochgeladen mit MsUpload

Datei:VR1-Original.jpg

2015-07-25T22:47:36Z

Omicron: Datei hochgeladen mit MsUpload

Datei hochgeladen mit MsUpload

HPCLJCP1510Repair

2015-07-25T22:43:36Z

Omicron:

{{Infobox Projekt
|name = Fix HP LaserJet Calibration Problem
|kategorie = Sonstiges
|status = in development
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = How to fix calibration problem of HP LaserJet 1510 Series Printer
|image = Logo-LaserJet-Calibration-Fix.jpg
|imagesize = 280
|version = 1.5
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1250 Series Printer (e.g. CP 1515n) is not working correctly (see top left part of image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration done > 3 times
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB) assembly
* Turn the ITB assembly upside down
* Take a photo of all 3 trimmer positions (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it)
* Turn VR1 right (for me 90 degrees worked fine)
* Follow the instructions of the service manual for re-installing the ITB assembly
* done

==Notes==
* This fix will certainly break warranty. Hence, only do it with printers being out of warranty!
* The fix proved to work for a single CP1515n printer. It may have to be modified for other instances.
* If changing VR1 on right PCB does not solve the problem, try the other trimmers (But always remember the original state!)
* When testing the effect of changing the trimmer, you only need to reassemble the following components
** The ITB itself
** The print-cartridge drawer stop
** The Print-cartridge drawer
* But (as always) be careful not to touch any live parts when the printer is connected to power!

Datei:Logo.jpg

2015-07-25T22:08:49Z

Omicron: Die Seite wurde geleert.

Datei:Logo.jpg

2015-07-25T22:07:24Z

Omicron: Omicron verschob die Seite Datei:Logo.jpg nach Datei:Logo-LaserJet-Calibration-Fix.jpg

#WEITERLEITUNG [[Datei:Logo-LaserJet-Calibration-Fix.jpg]]

Datei:Logo-LaserJet-Calibration-Fix.jpg

2015-07-25T22:07:24Z

Omicron: Omicron verschob die Seite Datei:Logo.jpg nach Datei:Logo-LaserJet-Calibration-Fix.jpg

Two photographs with parts of diagnostics page printout ("before" and "after") merged into one

Datei:Logo-LaserJet-Calibration-Fix.jpg

2015-07-25T22:05:51Z

Omicron: Two photographs with parts of diagnostics page printout ("before" and "after") merged into one

Two photographs with parts of diagnostics page printout ("before" and "after") merged into one

HPCLJCP1510Repair

2015-07-25T22:03:49Z

Omicron: Fix HP LaserJet 1510 Series Calibration Problem

{{Infobox Projekt
|name = Fix HP LaserJet 1510 Series Calibration Problem
|kategorie = Sonstiges
|status = in development
|autor = [[Benutzer:omicron|omicron]]
|beschreibung = How to fix calibration problem of HP LaserJet 1510 Series Printer
|image = IMG_20141103_113136.jpg
|imagesize = 280
|version = 1.5
}}
[[Category:Sonstiges]]
{{TOCright}}

=Objective=
The objective of this project is to fix a HP LaserJet CP 1510 Series printer having color calibration issues.

=Short version=

==Problem==
* Color calibration of a HP Color LaserJet 1250 Series Printer (e.g. CP 1515n) is not working correctly (TODO: Image)
* All attempts to fix the problem otherwise have failed:
** Update to latest firmware
** Repeated calibration done > 3 times
** NVRAM reset
** Reset to Factory defaults from menu
* The following other attempts were not done:
** Replace the ITB assembly (cost reasons)
** Buy set of original HP toner (cost reasons)

==Solution==
* Get the service manual (Google for "HP Color Laserjet CP1215 CP1515 CP1518 Service Manual")
* Follow the instructions for removing the Intermediate Transfer Belt (ITB) assembly
* Turn the ITB assembly upside down
* Take a photo of all 3 trimmer positions (labelled VR1, VR1 and VR2 on the two PCBs)
* Find the trimmer labelled VR1 on the right of the two PCBs (the board with 2 trimmers on it)
*