Increasingly Light Printing on HP LJ4200

[cmcdowell]

Hi, all - I'm hoping to get some help about increasingly light printing on an HP Laserjet 4200. The fuser's on the right settings with the right paper, high quality/density/darkness, new toner cartridge, and I've run multiple cleaning pages. It began just before we received our first "Perform Routine Maintenance" message, so I figured it was an issue with the fuser. However, even after I ordered and installed the appropriate maintenance kit (Thanks, PrinterTechs!), I'm still getting fading print.

I think it's a problem with either the DC Controller PCA or High Voltage Power Supply PCA, but I'm not sure how to test that without buying new parts. I have a copy of the service guide that tells me where they are and how to get to them, though. Should I try just taking it apart (with proper precautions) and making sure everything's connected or is there another method?

Thanks!

[cs_steve]

While the electronic parts you mentioned are possibilities, the more likely possibility would be either a dirty scanner mirror, or a second defective toner cartridge.

If you're up for cleaning the scanner mirror, you owuld basically remove the top cover, open the lid off the scanner assembly, and wipe down the mirrors with a Q-tip or similar.

[cmcdowell]

Thanks, cs_steve! It wasn't the mirrors but it did turn out to be two bad cartridges in a row - go figure. I'm relived it's not the electronics. Thanks for reminding me to check if the toner barrel was turning!