T-642, poor print quality. New cartridge tried!

[Oystercopy]

Hey Guys, a customer brought this machine to my shop, and we suspected a bad cartridge, but I replaced it with a new OEM Lexmark, same problem. Bad streaks and smudges through the page.
Any help appreciated!
OC

I tried to attach pictures to show the defect, but website glitch made it impossible.

[FrohnB]

What's your foam transfer roller looking like? Have had to replace those.
Have you inspected the fuser?
Aside from the cartridge, those are really the only other parts that could be causing it.

[Tech1]

It could also be the Charge Roller. It's located above the Transfer Roller. You can see it move up and down when you open and close the top front cover with the toner cartridge removed.

[Lance15]

It could also be the Charge Roller

+1

[Oystercopy]

+1

Could the charge roller cause this bed streaking to happen underneath the Paper as well, on the non printed side?

[Lance15]

The transfer roller could cause defects on the underside.

Replace the charge & transfer rollers.

[Oystercopy]

Thanks for the help guys! YES, the Charge Rollers are all "dimpled" and look terrible! How hard is it to change them? It looks like there's some kind of release on the left side, but can't seem to get my hands in there to confirm.
OC

[Tech1]

It's not hard you just need 3 hands and a light. The trick is to have something hold the top front cover halfway down (Lexmark used to send a little cardboard hook to use) while you release the left end first and then the right.