asked Aug 15, 2008 at 7:00am
Hp HP LaserJet 4100TN

hp 4100tn and 61X cartridge- spots

We have a years-old HP 4100tn printer that has worked beautifully until recently. It is used in an office to print reports and to print up membership cards on a heavy stock. No problems for years.

Recently, it was running low on toner. The printer had a "replace toner soon" alert, and the jobs were starting to look faded. Apart from fading, the jobs looked good and clean.

When the new cartridge came in, it started leaving spots on the prints after the first day. The spots were same shaped, and recurred at the same interval vertically on the page. So, I took the printer out for a good cleaning, installed the maintenance kit, and put it all back together. No change- the spots were still appearing.

Since the spots recur every 39mm, I looked for a roller that was 39mm in diameter. The only one is the PCR magnetic charge roller in the toner cartridge. To test this, I put the old cartridge in the printer- the spots were gone. New cartidge, the spots came back.

OK, so it is the cartridge. Possibly defective. We return it, and include examples of the spots for whoever at HP land does QC.

New cartridge arrives, is installed, and works fine for a day. Then, the mysterious spots return- again, every 39mm vertical down the page. These spots were in a different place on the pages, though.

Incredulous that we'd get two defective cartridges in a row, we again took the printer apart and thoroughly cleaned every thing in it. Blew it out with compressed air, vaccuumed the inside, replaced all the rollers we could, etc.

Still had spots. Since it once again seemed to be the PCR in the cartridge, we got another cartridge and installed it.

It worked fine for a week, but has now developed another set of spots.

Meanwhile, if we put the first depleted cartridge in, it prints without spots (but is faded since it is out of toner).

Is there some way the magnetic charge roller could develop a defect that would cause spots in print jobs?

If anyone has read this far could offer some advice or at least share a similar story, I would appreciate it. If I get this issue solved, I'll come back and post my solution.

Thanks in advance...

Are you sure these are HP toners, not remans?
Check the transfer roller for debris.
Spots on left or right?
Check exit assy. for dirty rollers.
by unknown on Aug 15, 2008 at 10:03am Add comment
They are genuine HP cartridges, brand new.

Spots are in different positions on each cartridge, always in the same place/interval on the cartridge.

On cartridge 1, there are two spots; one near center recurring every 39mm, the other towards right side also recurring every 39mm

On cartridge 2, there are three spots; two about 5 mm apart diagonal from each other recurring in same relative postition every 39mm, another 1/3 from right side recurring every 39mm

On cartridge 3, there is a small cluster of three spots near the middle of the page recurring in the same relative position every 39mm

The only roller I can find that has a 39mm diameter is the cartridge's magnetic roller. That and the fact that the spots change with each cartridge tells me that the cartridge has developed a problem.

Since the printer has been thoroughly cleaned, vaccuumed, all rollers and maintenance kits replaced, etc. I cannot find or imagine anything that has gotten into it to cause these spots.

We are beginning to suspect something with the stock that the users are putting through the printer; a regular paper stationary stock with 2 thicker stock credit-card-sized-cards stuck to it (they are printing membership cards).

The spots do not line up with the edges of the cards, and they have been printing these cards on the came stock with the same printer for years without problems.

Thanks for your reply, MichaelTech!
by HMNS on Aug 19, 2008 at 9:43am Add comment
The storage of the cartidges may be your problem. High humidity, temp, etc may be causing your problems. Are you buying from the same vendor?
by unknown on Aug 21, 2008 at 7:50am Add comment
If possible try a known good toner cart. from another printer.
by unknown on Aug 21, 2008 at 8:42am Add comment