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

[tonerjockey]

Hi Guys, i have been plagued on some of these with the intermittent jamming. one was consistent if i set it to 20, after 12 to 15, it would always pickup the the next sheet before the prior one was far enough so at the fuser, the lead had overlapped the trail edge of the one before it. i have one that jams if the tray is to full. one that jams if the tray is to low. i replace the tray 2 paper pick up and separation rollers and same thing. unfortunately the paper sensors are part of the fuser or paper feeder. and those units are very time consuming to remove and some are very expensive. and with no guarantee that it will resolve the issue. does anyone have any input? i have in the past exhausted all efforts calling 6 of the major HP parts vendors tech support. have removed one feeder. and i have one customer with maybe 15 of these and a third of them are now doing this. i wonder about the cassette lifting springs. the cassettes all look good. but this design lifts the paper up for the feed roller and then drops it down every page. any help would be greatly appreciated. have a nice day, Jim

[Iowatech]

I've seen this problem on older machines, so I don't know how much help this will be.
But for those machines, the solenoid associated with the paper feed timing was intermittently staying in the activated position because of noise reducing pads being worn, and the solenoid plunger or linkages would get stuck in the adhesive.
Cleaning the adhesive off would cure the problem. I never thought the machines were that much noisier with the pads removed, but other people around here would replace them with electrical tape or small pieces of rubber.
I have seen a solenoid plunger get so magnetized that it would remain in the activated position. But I've only seen that once, so I don't find that likely.

[NeoMatrix]

{random snip}

I never thought the machines were that much noisier with the pads removed, but other people around here would replace them with electrical tape or small pieces of rubber.
I have seen a solenoid plunger get so magnetized that it would remain in the activated position. But I've only seen that once, so I don't find that likely.

Re :Feed solenoid plate deteriorated pads have been removed.

The solenoid feed problem is not only with HP, it is also a problem with some old Kyocera and old Toshiba machines.

The noise of the feed solenoid plate/plunger coming together is not the problem when the plate rubber pads are removed. Depending on the solenoid resistive circuit, when the solenoid shuts off, you can still get enough collapse back EMF in the solenoid coil to hold the solenoid plates together metal-to-metal. Which gives the illusion the plates are holding together because of they're permanently magnetised. Replacing the sponge or rubber pad between the feed solenoid plate/plunger gives enough air gap spacing and assists the solenoid plate/plunger to come apart at the correct shut off timing.

The feed solenoid correct shut off time stops z-fold feed jambs and/or random registration problems.

Moral of the story: If you're having feed problems, replace the feed solenoid rubber pads where possible.

HTH

[theengel]

If I remember right, these don't have a solenoid for tray 2. Don't they just operate by a motor (M5)? I've replaced the motor on one of these (if it's the machine I'm thinking of) and it didn't help me at all.

What my machine was doing, was giving a misfeed error, and then going through a cleaning phase. The customer would have to press the ok button to continue printing. I replaced the feed roller, it got better for a short time, then the problem came back again. It was a new, OEM feed roller, so I assumed it was something else. After a lot of headache (including replacing the motor), I finally replaced the roller AGAIN. That was a few months ago, and it hasn't come back.

So you might consider ordering more feed & sep rollers from another vendor to get another batch, and replace those again.

[tonerjockey]

If I remember right, these don't have a solenoid for tray 2. Don't they just operate by a motor (M5)? I've replaced the motor on one of these (if it's the machine I'm thinking of) and it didn't help me at all.

What my machine was doing, was giving a misfeed error, and then going through a cleaning phase. The customer would have to press the ok button to continue printing. I replaced the feed roller, it got better for a short time, then the problem came back again. It was a new, OEM feed roller, so I assumed it was something else. After a lot of headache (including replacing the motor), I finally replaced the roller AGAIN. That was a few months ago, and it hasn't come back.

So you might consider ordering more feed & sep rollers from another vendor to get another batch, and replace those again.

well, when i had the feeder out a year ago on another one of them, yes, there is a motor, but i seem to remember a solenoid. but dont recall the foam? and when the one that was really consistent on a longer run around the 15th page, it would feed to soon. but that is still after the paper pick up roller was stopped. and in the past i did seem to try a second and even a third set of the feed and sep rollers thinking it was due to a defective sep roller clutch. but it usually always came back. strange design. and flimsy too.