HP color laser jet mfp M475dn intermittent tray 2 paper jams even after new rollers.

[tonerjockey]

HP laser jet 400 color MFP M475 this is a re post from the printer section. i have been plagued with several of these that will jam intermittently, especially after 15 pages. watching the paper under the pick up roller tray 2 it almost seems that it is a separation problem. but the pick up roller is clearly starting a little to soon, causing both the trail edge of the earlier sheet and the lead edge of the last fed to be at the fuser entrance sensor at the same time, signaling a jam. it is really aggravating as its hard to watch it and try to determine what the cause is. i have removed the tray 2 paper feeder assembly from one. there was supposed to be an obvious broken part that would cause this. but i saw nothing that looked in question. its a strange system that both raises the paper in the tray and also starts the rotation of the pick up roller at the same time. pain in the arse as i have one customer now with 6 or so that are now not reliable. also the sensors are either in the feed unit, or in the fuser. other causes could be DC controller. all of these items are a pain to remove on the duplex models and also nearly cost prohibitive to just try swapping out parts. i have replaced the paper pick up and separation rollers on these, sometimes several times with OEM to no improvement. might anyone have any experience with these POS machines with this problem?? thank you very much, Jim

[copydocinc]

Re: HP color laser jet mfp M475dn intermittent tray 2 paper jams even after new rolle

I would be looking at paper feed solenoid getting stuck open.

[tonerjockey]

Re: HP color laser jet mfp M475dn intermittent tray 2 paper jams even after new rolle

I would be looking at paper feed solenoid getting stuck open.

thank you so much for replying. ok, i was wondering that too. the problem is, the roller always stops like its supposed to. but then when it decides to, usually after 12 to 15 copies, that short delay, where the roller stops and the paper feeds out of the drawer, it starts a mili second to soon, and then there is a slight over lap of the two sheets at fuser. i watch it, and at the paper feed roller, there is usually a half inch space between the lead and trail. when it fires to soon, there is maybe a quarter inch or less, but i suspect that the vertical transport or fuser may be turning a little faster, as the slight gap is closed by then. its a pain to catch it, as i have to run a few sets of 20, while looking thru the gap of the paper drawer and the machine and with flashlight watch the paper and roller. watching the "KaChunk" just as the prior sheet passes the roller. happens quick. thank you, Jim. have a great Thanksgiving.

[tonerjockey]

Re: HP color laser jet mfp M475dn intermittent tray 2 paper jams even after new rolle

i offered to the customer to replace the paper feed mod, with no guarantee that it would have the desired outcome. they have not asked me to do so. after thinking and looking at the timing chart again, i see that the motor starts, and almost the same time the solenoid fires. so, you may be correct. if the motor stops before the roller would make a second rotation, then as soon as the motor starts, the roller would turn, possibly prematurely. i will post a outcome if they decide to do it. have a happy new year guys. Jim

[JrTech]

Re: HP color laser jet mfp M475dn intermittent tray 2 paper jams even after new rolle

Definitely look at the feed solenoid as they can be deceiving by looks. These are nice machines and I rarely have issues with any HP unless as most people do and use generic parts, supplies. Although it keeps me busy. First thing is remove the covers and run the machine like you are doing now. On some of the earlier models the little blue piece of felt (damper) on the solenoid would become sticky enough to hold the solenoid open or closed just a tad sec too long throwing jam codes. Just replace the solenoid and use OEM parts and you won't see the issue arise again till a few hundred thousand pages go thru. Also can be the paper as well, if paper type is not correct in the menu it will cause issues down the road with feed components. I have seen generic rollers causing paper feed component issues. Hope this helps.