Sollid Yellow printing

[Mchissano]

I am fixing a HP color laserjet Printer, that has a solid yellow printing on paper backgroud, 

i have already checked the yellow drum, cartridge, replaced the HVPS-D, clened the connectors of cartriges 

the issues persist. 

the attahced files shows issues with drum 1 and with drum 2

what i am supposed to do to fix it ? 

Drum 1Drum 2

[Kuroi_Kenshi]

Hi @Mchissano,

Welcome to the HP Support Community!

Thanks for reaching out!

We're thrilled to have the opportunity to assist you and provide a solution.

I understand your HP Color LaserJet printer is producing a solid yellow background despite replacing the yellow drum, cartridge, and HVPS. Let’s go through a few checks.

Based on your description that you have already replaced the yellow cartridge/drum and the High Voltage Power Supply (HVPS-D), but the issue persists, the problem is likely related to the laser scanner assembly or a persistent charge failure on the yellow developer roller, possibly caused by excessive contamination or a faulty, in-stock replacement cartridge. 

Here is a step-by-step troubleshooting guide to resolve the solid yellow background:

1. Perform the "Half-Self-Test." 

To isolate if the yellow toner is being applied before or after the imaging stage:

• Print a plain page.
• When the paper is halfway through the printer, open the front door to stop the print process.
• Remove the toner/drum cartridges.
• Check the Intermediate Transfer Belt (ITB): If the yellow background is visible on the belt, the issue occurs during the developing stage (toner/drum).
• Check the Drum Surface: If the yellow color is already on the yellow drum unit, the cartridge is likely leaking or receiving a wrong charge. 

2. Check the HVPS Contact Springs

Even if you replaced the HVPS board, the issue might be the connector springs that interface between the board and the cartridge. 

• Inspect the contacts inside the printer where the yellow drum/cartridge connects.
• Look for bent, broken, or contaminated springs. Toner buildup here can cause a short, leading to improper charging of the drum. 

3. Check for a Faulty New Cartridge (High Possibility) 

It is possible that the new cartridge is defective (e.g., leaking yellow toner). 

• Reinstall the old yellow toner/drum, if possible, to see if the solid background changes.
• Ensure that the "protective plastic shield/tape" has been completely removed from the new cartridge. Sometimes the tabs or protective film are not fully removed, which can cause this issue. 

4. Check the Laser Scanner Assembly. 

If the yellow color is uniform across the page, the laser might be firing incorrectly.

• Clean the laser scanner windows if they are accessible (often, toner dust gets on the mirrors).
• A faulty laser scanner unit may need to be replaced, particularly if the issue is a persistent solid block of yellow. 

5. Run a Cleaning Mode 

• Run the "Cleaning Page" or "Calibrate Color" option from the printer's maintenance menu multiple times to remove excess toner from the transfer belt. 

6. Verify "Black Only" Output 

If the issue is still not resolved, try printing a document in "Black Only" or "Grayscale." 

• If the page still has a yellow background, the issue is almost certainly an HVPS/contact issue (the yellow is being transferred improperly during the black print cycle). 

I hope this helps.

I'm glad I could help! 😊 If this resolved your issue, please mark it as "Accepted Solution" and click "Yes" on "Was this reply helpful?" Your feedback not only keeps us going but also helps others find the solution faster! 👍✨

Take care and have an amazing day ahead! 🚀

Best regards,

[Mchissano]

Hi. 

thanks a lot for your support, 

when i simulate a isolated print, blank page, it comes right, doesnt print yellow, 

when i print a black and white print, it prints very well

the sollid background yellow only happen when there is any color 

eg. printing a supply status, or any page containing a color 

i bilieve there is some issue with the interface conectors 

how can i perform  test on it?