87vert

asked Jan 2, 2007 at 3:16pm
Hp HP LaserJet 4250

HP 4250 picking multiple sheets

I have an HP4250 that is picking up multiple sheets when printing from tray 2. I have replaced the pressure rollers, tried a new tray and it still jams. The problem is intermitent I can print a 50page paper path test with no problems but on the next job it might pick up 20 pages. I have made sure they are using new paper and not trying to reuse already printed on paper.

Any ideas on where to look next?
I have heard that sometimes this can be caused if the tray backstop is not in the right position. Being off by a little can cause the paper to move back & cause multi-picking
by wpc on Jan 2, 2007 at 3:18pm Add comment
The backstop being out of adjustment is common on Color LaserJet 4600/4650 printers.

I would not expect it to cause the same type of trouble on a 4200/4250 as these printers have a separation roller. (the 4600/4650 do not)

The first thing to try is to bend the paper in a "U" shape before loading it.
by Stephen on Jan 2, 2007 at 6:54pm Add comment
i've tried faning the paper before. It works great from the manual feed so its something in the bottom of the printer maybe the feed assembly?
by 87vert on Jan 2, 2007 at 7:19pm Add comment
The only thing which is responsible for making sure only 1 sheet of paper is fed thru is the separation roller in the tray. Nothing in the pickup assembly in the tray cavity can cause mutiple sheets to feed. If it is not the separation roller and since you have tried another tray, then the only thing left is the media itself.
by dmzcompute on Jan 2, 2007 at 7:27pm Add comment
i was thinking the media also, im bringing over a new pack of decent quality paper that i've used in my 4650 with no problems. so we will see. thanks guys
by 87vert on Jan 3, 2007 at 4:41am Add comment
It was the media, they were reusing old paper and would replace it with new stuff whenever I came. Thats why it always worked for me and not for them. I surprised them this time and caught them in the act.
by 87vert on Jan 3, 2007 at 11:48am Add comment
I hope you charged them for the call. - moe
Fanning the paper can put a static charge on it. (which can cause multifeeds)

Bending the paper in a "U" shape does not put a charge on it.
by Stephen on Jan 3, 2007 at 5:48pm Add comment
try replacing the cork pad
by Anonymous on Jan 9, 2007 at 8:45am Add comment
Please disregard the posting by Anonymous as he obviously knows nothing about this printer and should not have posted incorrect information.
by dmzcompute on Jan 9, 2007 at 4:07pm Add comment
I had been having the same problem with a 4250 and it was fixed by adjusting the backstop (as mentioned in the first note). When I added paper to Tray 2, the backstop was being moved back just enough to cause the printer to pick multiple pages. Now that I know what's causing the problem, I always make sure the backstop is tight against the paper after adding paper. I don't have the problem anymore.
by Anonymous on Apr 10, 2007 at 9:10am Add comment
The backstop being off will cause multiple pages to be picked, but... the separation roller should push them back into the tray.

So you may have a worn separation roller.

And there is always a slim chance that the torque limiter on the separation roller mounting shaft is bad.

The torque limiter is the black thing the separation roller is driven by, if you hold the gear at the outside end of the separation roller shaft and then turn the roller by hand it will turn but with some drag, you can also take the torque limiter off the shaft and turn it by hand, it will feel fairly tight.
by Stephen on Apr 10, 2007 at 5:00pm Add comment