M570DN printing yellow over entire print area for all color prints (other colors still present)

[Random90851051]

Hi all,

Here's some additional info:

• History:
• It’s been used for light office duty for 6+ years
• No serious issues ever experienced with this unit
• The issue began as an intermittent problem and has now become consistent
• The yellow is dark (consistent) and covers the entire printable area (with clean lines on the margins)
• Some Relevant Steps:
• Good configuration test page (B&W), bad demo page (color)
• Changed yellow toner cartridge (both were HP, no mods/refills/generics) – no change
• An engine test shows no issue – all lines are present, clear, and straight
• An engine test with Magenta and Yellow swapped showed no difference (no issue, just swapped line placement)
• The above steps suggests that the issue is before the engine – not the toner/drums/etc
• Formatter has never been removed and, in this model, isn’t mounted to a module (so dirty contacts aren’t an issue)
• Event log registered a “Yellow CPR pattern can't be read” but I’m not sure when in the process that happened (didn’t look at the log until after the above steps).  I may have created some log entries when swapping the cartridge locations

The above seems to point to either a formatter or DC controller.  Are there additional troubleshooting steps (or info in the above) I’m missing that would allow me to narrow down to a singular, most-likely-faulty component?

I appreciate any help!

[Valsimot]

When you disable the cartridge check swap toners M and Y and print the demo page is it yellow or magenta?

[Random90851051]

Thanks for the quick reply. 

I haven't been able to find that setting.  I've seen references to it but my printer's WebUI looks different than all I've seen and there isn't anything that clearly relates to "cartridge check" or "cartridge swap", etc.

Also, I attempted to print a demo page from both WebUI and front display.  I also tried to see if I could wave off the error with the front display (even with the unlit keys).  No luck.

Any idea where that setting is or how to get around the lack of it?

[Random90851051]

Apparently, this is still an intermittent problem but just over a longer period now.  I had someone need to print while I was trying to find the menu option to disable cartridge swap prevention.  I temporarily put the toners back in the proper order and then had color prints working fine (including a demo page).

Given nothing has systemically changed, the yellow 'background' will recur (likely today).  I'm happy to try any additional troubleshooting steps mentioned as soon as it does.

[Valsimot]

Maybe you had a poor contact that is now good after the toner swap. In a case, an issue appears on the printer screen go to Administration -> Troubleshooting -> Diagnostic -> Disable cartridge check  swap Y and M to see what will happen.

After that, you can swap toners, or remove toners and the printer will print without checking cartridges.

Also please take a photo of the interior of the printer the backside mechanics with gears the part where toner goes in both for Y and for M and post here.

[Random90851051]

Thank you for the reply.

If it was a contact issue, I would have expected:
- My previous cartridge swaps to impact it (Y - M and yellow cartridge replacement)
- The engine test to have shown something other than clean lines

The picture of the contact area is attached below.

Regarding "Administration -> Troubleshooting -> Diagnostic -> Disable cartridge check":
Neither the WebUI nor the panel UI have that tree structure.

I see the path you mentioned in two places:
- LaserPros.com: DISABLE CARTRIDGE CHECK
- HP.com: Disable cartridge check for Swap Procedure

However, my menu is roughly (derived from printing menu structure):
Setup
- HP web svcs (not interesting)
- Reports (not interesting)
- Self Diagnostics (not interesting - only has FAX)
- Fax Setup (not interesting)
- Network Setup (not interesting)
- Quick Forms (not interesting)
- System Setup: didn't see an applicable setting
- Service: didn't see an applicable setting

[Valsimot]

Sorry, that printer model doesn't support disabling cartridge check for diagnostic purposes.

The contacts inside the printer look good as I could see. It could be to the main drive not engaging Y toner proper.  The colour toners are not engaged in the print engine when you are printing only black, but when you switch to color printing all 4 toners are engaged and it's possible that in that process of engaging-disengaging Y toner something goes wrong.

[Random90851051]

No worries on the lack of support for disabling cartridge checking.

Understood.  When I looked at the contacts, I couldn't see anything on them either.

What's interesting about the engine test is that it does engage the other colors too (not just B).  I get the pin striped page and never get the yellow issue.  I even performed that test back to back with two other demo page tests (to make sure I wasn't getting luck on the timing).

[Valsimot]

Good notice. The engaging-disengaging mechanics don't work the same when printing an engine test page compared with the printing demo page.

[Random90851051]

Ah, I thought it went through the same process.  Thanks!

Testing this again today, I have reseated the Y, rebooted the printer, and printed from two different computers.  I am now unable to reproduce the problem.

I will continue testing and reply if/when I can reproduce the issue.

Thank you again for your time.