asked Jan 26, 2013 at 7:54pm
Hp HP LaserJet 4100

Laserjet 4100 stalls ...

We have about 12 Laserjet 4100n printers at my school, all of which have developed the same issue.

If you have them print multiple quantities of something, they will print a random number of pages (perhaps 10-20) then send a blank page and stall. The motor continues to run, the screen will state "processing job" but nothing happens. If you open and close the front cover and press the "go" button it will print a few more then stall again (usually after printing fewer pages).

If you do a duplex print, which slows down the print process, it will print more pages and may even complete the job. Under the direction of HP, I tried doing a paper path test ... printing from tray 2 single-sided, it stopped after about 8 pages. Duplex printing from tray 2 it finished the "test" with 50 pages OK. Printing from tray 1 -- which picks up the paper slower than tray 2 -- it also competed the test, though I only tried it once.

NONE of the printers have ever had maintenance kits installed. Do you think it is possible that -- even though there is no set error code -- something is up with the fuser tripping something? I first thought it was the formatter (main?) PC board, but after being able to print the jobs with a slower feed, I now question that thought.

Duplex jobs don't necessarily always print fully, but it is interesting that they finish more often.

Any thoughts are appreciated. Weird that all the printers developed the same issue over the past year or so.
The infamous sticky pickup roller solenoid issue. There is a sponge dampener that has disintegrated into sticky goo. The solenoid heats up and the goo gets stickier and holds the release plate allowing the pickup roller to turn when it is not supposed to. If you feed from the MF tray, you'll see that the problem does not occur.
You will need to separate the printer from the tray to access the solenoid. It is located in the tray at the front right corner. Remove the solenoid, take off the release plate and spring and scrape off the goo. Replace it with
There's enough included to do all 12 printers.
by moe on Jan 26, 2013 at 10:37pm Add comment
"Weird that all the printers developed the same issue over the past year or so."

Not really, they're all roughly the same age.

accessing the solenoid takes quite a bit of time and disassembly of the printer.

If you're enterprising, it is possible to repair the solenoid without replacing the dampener material, but I'm sworn to secrecy about the method.
by eric111 on Jan 27, 2013 at 9:12pm Add comment
This kind of reminds me of the guy who's selling a secret repair method on eBay to clean HP color laserjet 2600 scanner mirrors without disassembling the printer (slight modification he calls it). Since the scanner mirrors are inside a box that's behind all kinds of plastic, metal, wiring and it's on eBay, it makes me wonder. Since the 4100 solenoid is under a metal plate with absolutely no access, I kind of wonder. Over the years, I've come up with a few solutions how to replace dampener material on other models without disassembly or minimum disassembly, but I have to call you out on this one. - moe
I'm afraid this method could fall into Russian and/or Iranian hands, or even worse, that evil Wikipedia guy...and then it would be a huge problem for the UN. Sorry, I ain't talkin'

by eric111 on Jan 28, 2013 at 11:26am Add comment
It's OK, I know where you live and work thanks to Google. I have my ways of making you talk. - moe
Wow ... thanks for the tips. I am on a mission now ... I will let you know how it goes.

Thanks again.

by rwagoner on Feb 2, 2013 at 12:20am Add comment
AMAZING. The printer works PERFECTLY now. And the repair was so easy as well. Thank you!
by rwagoner on Feb 6, 2013 at 12:27am Add comment