P2035 light/low density print

[dcol]

I am at wits end with this printer. One day it decided to print uniformly light across the entire page.

I replaced the cartridge with brand new HP, Didn't work. Tried another one, didn't work

Then replaced laser module. Didn't work

Then replaced DC/power supply board. Didn't work.

Replaced transfer roller. Didn't work

All parts new HP. Cleaned all contacts to cartridge. Fuser working properly.

Tried on two different computers and with self test, so not a driver issue.

What is left to do?

Any help is greatly appreciated

Thanks.

[dcol]

Do not post any phone number as its a support scam.

Looking for suggestions, not paid services.

[Valsimot]

Have you tried resetting printer to factory defaults?

What about engine test how it looks?

A scanned image of printers demo page so we can see a problem would be nice.

[dcol]

THANKS for responding!!

yes. Tried factory reset.

Engine test prints 11 horizontal line (very light) on the paper

here is the test print

[ALS-77]

Some options to try:

You can resolve some print-quality problems by adjusting the print density to make the overall printing lighter or darker.
Windows driver:

1. Open the printer-driver Properties screen, and then click the Device Settings tab.
2. In the Print Density area, adjust the slider bar to change the print density.
3. Click the OK button.

Go into the EWS (Embedded Web Server) of the printer to see if there are print density options to adjust. 

Try a print stop test where you start a print job and open the cover of the printer with the paper half way thru, then pull out the toner cartridge and check the print on the drum surface to see how dark or light it is. If it's dark, but only transfers a light image to the paper, then it's an image transfer issue, which should have been fixed with a HVPS replacement, but could be a contact problem with the transfer roller or toner cartridge.

If it's light on the drum surface, then it's an image formation issue, which also should have been fixed with a HVPS replacement, but could also be a contact problem with the toner cartridge.

Check all the contact points inside the printer for the cartridge to make sure they are not damaged and are in the right position.

Make sure  you're plugged straight into a wall outlet and not a power strip, surge protector or UPS.

[dcol]

Thanks for the great reply.

Did all that. Comes off the drum light so I suspected the transfer roller first or the laser unit. Neither of which are bad, and this printer is relatively clean and all of the contact points are good. Go figure.

Been working on HP lasers for 30 years and this one got me stumped. Picking up another printer same model that I can use to test all these parts in. But I suspect none of the parts are bad. If I finally figure it out I will post here in case anyone else runs into this.