LJ 4000T thermal problem - looking for suggestions

[rpeterson]

Hello all, and thanks in advance for your help and suggestions.

I have a LaserJet 4000T which seems to burn toner on to the roller in the cartridge, resulting in one to two thick black horizontal lines, that run the width of the roller.

At first I thought it was the cartridge itself, but it did it with a new cartridge as well. Interestingly, if I scrape the burned on toner off the roller in the cartridge, it will be fine for a while, but after going into sleep mode or sitting idle, toner will once again be burnt on.

This seems like the thermal unit that isn't shutting off after printing, leaving the heat to burn the toner to the roller... Any suggestions? Anyone seen this problem before?

I'd appreciate any help, thanks, Ross

[Brian]

Am I getting this right? do you have toner build up in the cartridge? not in the fuser.
Black lines in the cartridge aren't a thermal problem, it's wear of the drum, scraping any residue off it will damage the drum even more, black lines on a new cartridge could be casued by dirt in the printer.
Do you use original HP cartridges?

[ptjeff1]

As Brian said, are you referring to the fuser or toner cartridge?

If you are talking about the toner cartridge and the photosenistive drum getting black lines...Have you recently replaced the transfer roller? There have been some bad aftermarket transfer rollers manufactured for the Laserjet 4000. Some cause damage to toner cartridges like you are describing. I know it sounds weird but from what I've heard a very very large parts supplier had some problems with this. Try an HP (OEM) transfer roller if you are using an aftermarket roller.