asked Oct 26, 2007 at 4:09pm
Hp HP Color LaserJet 3700DN

HP LaserJet 3700DN printing vertical lines

So I'm a "Printer Repair Guy" at Oregon State University, and I recently went to look at a LaserJet 3700DN. It's printing vertical lines down the page with some confusing symptoms. The lines only occur after printing about 35 copies at a time and, starting with copy number 32-38 the lines get steadily worse. What confuses me is the fact that the first page of the next print job always turns out just fine. It will go from page 50 of one job, covered in lines to page 1 of the next completely fine.
Now, it only happens with black as far as I can tell (there isn't much color in the path tests and I don't know haw to print 50 demo/config pages in the same job) and I recently replaced the fuser due to another problem. The transfer belt still has plenty of life as do all the toner cartridges.
My guess is that one of the cartridges or the transfer belt is to blame - as the lines start at the top, end at the bottom and are always continuous. they are using re manufactured cartridges so I told them to replace it and see what happens. But I'm still not 100\% and I was hoping for a second opinion. My boss is out of town this next week so I'm on my own for this one.

Need a description of the lines. Are they evenly spaced, or random? Thick, thin, regular, irregular? Do they start right at the top edge and end at the bottom edge, or is there a little margin?
by moe on Oct 26, 2007 at 4:24pm Add comment
They start right at the top and end right at the bottom. They're thin lines, usually not-quite solid and spaced randomly from print job to print job, but within the same job on different pages they always occur in the same place. there isn't any rhyme or reason to the spacing between the lines, and since they're vertical and constant I can only assume it isn't a typical roller or the fuser.
new thought: a blur in the laser lens maybe? but that still doesn't explain why it only starts acting up after 30 some prints.

by Brante on Oct 26, 2007 at 4:34pm Add comment
Doesn't sound like the laser scanner. I think your on the right track with the cartridge being the issue, but i agree that is an abnormal problem if it is the cartridge since it only happens randomly. Check the contacts on the left side when you pull the cartridge out. How do they look? Do a disable cartridge check and swap the black with another cartridge. Does the problem follow the cartridge or does the other cartridge have the problem?
by Anonymous on Oct 26, 2007 at 5:08pm Add comment