Clean the LED for K (Black) in the machine (Pull the stick out, put it in, repeat a few and try again)
If it still is faded, try swapping the black imaging unit with another one(think magenta), if you print 10 copies or more and they all are the same, it isn't the imaging unit, if it starts to mess up Magenta you have the problem sorted out.
If it isn't, look to the belt cleaner (I don't think this will be it since it doesn't affect all colors, just the one)
Not sure if this fix applies to this machine, but give it a try if it does
If it is only black, and black is being made from 4 colors, try Use Pure Black in the driver
Hi. I'm new to the forum. My Phaser 7500 DN is having a issue where all other colors are printing sharp and crisp with the exception of the black. The black is coming out almost bleeding and misregistered and spotting. All the other colors are coming out crisp and clean. Just to speak openly, was using third party toner and imaging units but now have on order everything new OEM consumables. What could be the issue here? Could it be a dirty belt drive or maybe the Regi Com Control is off? Any help would be appreciated. P.S-Above are links to pictures I took of what exactly is happening and I saved in my google photos.
Thanks in advance