Kyocera 420/520 series doc feeders plate not rising.

[Tom]

KJG is absolutely correct about what is happening. I had some time today to mess with it, here's the symptom. Cam does not turn and allow plate to rise. If you put pressure on top cover assy that contains feed belt it will then raise and continue to raise until the next time you open and close the top cover and then problem repeats. I tried opening the cover while keeping the interlock closed and I can see the cam move a bit but it stops and doesn't raise the plate. I think this feeder has another way of knowing the cover is open and when it thinks it is it won't rotate the cam to allow the plate to rise all the way. Now get this, I took the gear off that drives the feed belt/PU roller and closed it back up and the plate rises every time. Of course, without the gear it can't feed, but this proves to me it's not a motor problem. Put the gear back on and it doesn't rise unless you press down on top cover and then it will engage and keep working until opened again. Argh. I checked and the gears are engaging and turning the feed belt/PU roller. KJG says replacing the top cover assy fixes the problem, but for the life of me I can't figure out why it would or what's causing it to act so weird.

[kjg]

I sure hope you can see something I don't.

I would like to know what truly causes it.

I have a hunch the cover warps up in the center over time and causes the difficulty.
I have had customers who were billable and didn't want to pay for the price of a new cover just park a stapler on the top cover over the feed head and they never had the problem come back. Yeah, I know its a very bad place for a stapler. But it works.
Remember, the feed shaft is only a half shaft and not a full shaft. I think that plays into the problem quite a bit over the course of time.

Originally I had thought it had something to do with the sensor on the front of the white plate (reading guide) on the bottom of the ADF but could never link that to the symptoms.

Please post if you find out anything different.
KJG