Is there a self diagnostic test that I can run on my HP 2600n? My magenta cartridge is not right.

[eaholden]

My magenta cartridge is not printing well. I replaced it with a new one. The printer has printed about 16,000 color pages. Is there a diagnostic I can run?

[Apone]

you can access a troubleshoot/diagnostic menu through the control panel.  i'd recommend a disable cartridge check.  it'll allow you to switch the toner into different slots and you can test print.  so for example, if you switch the magenta into the cyan and cyan into magenta slot, and the cyan shows the same defect the magenta was originally showing, the problem is probably not the cartridge but something hardware related (like the laserscanner)

[Valsimot]

The most common problem on this model is dirty laser optics, special for magenta because magenta toner is lowest in the printer and all dust is falling down on magenta laser optics making them dirty and print in magenta very light or none.

Probably all you need is to remove laser, and clean optics for all 4 lasers ( recommended)  it's not a complicated job if you are handy with tools, I have cleaned more than a 100 of these, it's a 20-minute job for me. What you need to do is very fast shown in this video https://www.youtube.com/watch?v=2Y6gkQL9FM8