Laserjet 4M: dirty printing still

[shilkman]

After having thought I had fixed this problem with a new toner cartridge and transfer roller it has come back to haunt me! On the reverse of my prints I get horizontal banding and a general peppering of toner giving it a dirty appearance. See the picture I took of the reverse side of a test print I did. The printed side of the print is fine. The problem seems a little less severe if I leave the printer on for about 30 minutes before doing a print. Any suggestions greatly received. Is this a fuser problem perhaps?
Regards

137

[Big Al]

Chances are it is the toner cartridge. Most of the # 98 cartridges have been refilled several times and can sometimes leak some toner. Use a can of "air" (really compressed gas) and blow any loose toner off the transfer roller. Then do a Half Page Print test. Lift up the lid just as the paper is going through the print station. You may have to try it a few times to get it right. If the loose toner is deposited on the back then you have a toner cartridge issue. Try it several times. If all looks well here then print some test pages and if the problem returns, do another Half Page test. I suspect toner is leaking out and contaminating the transfer roller.

You could also pull the fuser and inspect it.

Please let us know what you find.

Al

[shilkman]

I suspect toner is leaking out and contaminating the transfer roller.

You could also pull the fuser and inspect it.

Please let us know what you find.

Al

Thanks for you comments

Should the transfer roller be covered in toner anyway as when I pull it out to look at it IS always coated in toner? This is the second new cartridge I'm on from different sources so I would hardly think they would both be leaky? The fuser looks ok and I will try your test.

Regards

[MichaelTech]

Possibility of the H/V being full of toner, and shorting a bit. Pull tray, lift printer on its back, two screws, pull off H/V and clean.

[shilkman]

Possibility of the H/V being full of toner, and shorting a bit. Pull tray, lift printer on its back, two screws, pull off H/V and clean.


Okay...thanks, I'll check that.

Regards

[shilkman]

Lift up the lid just as the paper is going through the print station. You may have to try it a few times to get it right. If the loose toner is deposited on the back then you have a toner cartridge issue.
Al

Well it gives a rather black band fading to grey on the back of the paper. But oddly repeating the test several times its now fine and is also producing decent prints again. So perhaps the first test cleaned the transfer roller? And how long will it stay like that? There is no evidence of surplus toner coming out the cartridge into the machine so I'm not really sure what is going on.

Regards