HP Laserjet 4000n still paper jams

[Zachary]

Further down in this forum you'll find my original thread about this, I've replaced the rollers (there were three right?) AND the fuser, I've also updated my driver to that of HP.com (running it on XP Home SP2) and done a cold restart yet the problem still persists. After replacing the rollers and fuser I get paper tray jams in tray 2 more often, yet when I open it there is no sheet in the rollers at all, after that I immediately get the Rear Door paper jam error as before.
Here are some details:
Page count & Pages since last maintenance: 125848
Memory: 8mb
Last three errors:
Number | Error | Page Count
30 | 13.20.30 | 125847
29 | 13.1.50 | 125847
28 | 13.20.30 | 0

Are there any further possible solutions?

[Fast Response Service]

LOL! Ive got the same problem, Ive replaced the maint kit, reg assy. paper feed assy. pca board, output assy. still has the same damn problem! Now to save face with my customer im gonna cheat! Im buying another refurb printer and swapping the panels and changing the info in service mode to look as if its there printer! then I can take theres in the shop and take my time and figure out exactly which part is bad thats giving the problem! AGH! almost enogh to make a preacher curse!! LOL! Im suspecting it may turn out to be a flakey sensor but time will tell~

[Zachary]

Please when you figure it out let me know, unfortunately buying another one isn't an option for me so I must figure out how to make this one work or live without a printer for a while....

[ptjeff1]

I don't know how intermittent the problem is but if you can observe the problem in action this might help. Print a continuous paper path test from tray 2 and watch the paper being fed from the back of the paper tray. You should see the 4 'D-shaped' pickup rollers moving the paper forward and the feed roller pushing the paper up into the printer. If the rollers slip you might have a bad set of rollers. If you have genuine HP parts this wouldn't be a problem but some aftermarkets parts use a cheap rubber that doesn't work very well. You also may have a problem with a paper sensor or the paper feed assembly.

[Zachary]

The paper path test went fine, when it prints though it always sends an extra page through the printer and it just sits there in the fuser...blank, sometimes it reports that as a paper jam. In the paper tray it also begins feeding a new page but that seems like normal behavior, just waiting for a new print job.
Also, whenever I print something from the printer (Config page, menu map, the paper path test) it goes fine, the jams only occur when I try to print something off my computer.

If it's unclear what I'm talking about I can take pictures

[MichaelTech]

Ah,, the double whammy! Top cover, rear door! Error!
The feed sensor and the reg. sensor are under the chassis.
These are giving this error. Weak/missing spring.
Remove the reg. assy., the feed assy. and blow out the sensors.
If worn, replace the feed assy.
Also check the exit sensor flag.

[Fast Response Service]

I had another unit come into the shop this week same issue, what I did to solve it was tear the feed clutch apart and clean it very very good with a 3M scuff pad and clean the shaft it goes on, at the end of the shaft theres a 2nd gear with a 1 way bearing, I took emery cloth and scuffed the shaft up pretty good, make sure and clean everything afterwards so theres no debris or residues left behind. I checked the sensor flags and sure enough they were worn down a bit and shiny, I used an old trick told to me by an old timer and used a drop of super glue and used a hair dryer to cure it. after it was dry I rubbed my finger over it to make sure it was smooth with nothing jagged to catch paper on. I also took the reg assy out and cleaned the end bushings and cleaned the rubber shaft and scuffed it up with the emery cloth, wiped everything down really good and blew compressed air in all the sensors and bushings. I re-assembled everytghing and ran test after test with no 13xx codes. it worked for me but it may not work for you. but what the heck you have to lose? hope this bit of info works

[Fast Response Service]

I brought a 4000n into the shop today with the same symtoms, I checked everything with no success, then I noticed the cassette guide that ajust for the paper length at the back had popped out of the notch causing the paper to intermittently slide back just enough to see it as a4 size, I repositioned the guide and made sure it locked into place and ran 5 runs of 50 with no Jams

[redcow]

Humor me, Check your paper size settings.

If you replaced the rollers and fuser, the page count since last maintenance should be a much smaller number.

From the manual feed tray, can you do a paper path test with a count of 50. Or does that fail also?

[Zachary]

Sorry for the delayed response, I've been very busy lately...I don't know very much about the anatomy of this printer so could you please be more specific about cleaning/replacing parts. I had to look at step by step instructions to replace the rollers & fuser.
Also, how do I check the paper size setting? I did a cold restart which should have put it at Letter size, right?
As for a paper path test from the manual feed tray, I don't know how to perform that, I've never even used that tray before...if you'll please explain how I'll be glad to try it. Thanks :)

[cs_steve]

Redcow is referring to the physical paper size settings, not the "formatter" settings which you reset with a Cold Reset...if you pull your tray out of the printer, you will find that it has blue paper-size adjustors inside the tray...there is an adjustor on the sides of the tray for paper width, and an adjustor at the back of the tray for paper length... make sure these are set for "Letter "

To do a Paper Path Test from Manual Feed Tray (Tray 1, "fold-down" tray):
insert 50 pages or so, go to the Information Menu, press Item button until you see "Print Paper Path Test"...press Select, it will say "Input Tray=1", press "Select", it will say "Output Bin..." press Select, keep pressing Select until you see "Copies=1", stop and press the Value button to increase the # of copies to 50. Then press Select and it will begin printing 50 test pages from Tray 1.
You are running this Paper Path test to determine if the problem only happens with Tray 2, or if it happens from either Tray...

BTW, since you're not that familiar with this printer, you're probably going to end up needing to have a technician/repair shop look at it... the tips some are giving here are good tips but are probably intended for people fairly comfortable with assembly / disassembly of parts on this machine...