Ricoh MP C4500 ADF jamming

[techd]

hi i have a ricoh MP C4500 that is jamming in the ADf unit, i have replaced the BY-Pass Roller & Paper Feed Belt, the rollers just spin and don't pick-up any paper, everything looks good no noise, any one ever come across this problem if so what was the fix and any help suggestions are welcome.

[Fearless V K]

Check to make sure the actuator for the up/down movement of the pickup roller is meeting up correctly with the arm on the roller assembly. I have seen the arm get jammed under the actuator if the assembly is removed and reinstalled incorrectly.

[Cipher]

the rollers just spin and don't pick-up any paper

I have seen many intermitten problems with the pickup roller collar not always moving across and engaging with the teeth of the pickup roller when drive is supplied.

The collar needs to be completely free of dirt, paper dust and scuf marks to slide freely.
What ever you do don't oil this area it will have the opposite effect and bog the movement down.

Also don't forget to clean the inline sensors and black felt backings (especaily the one underneath the DF secured with two screws).

[Canadian Tech]

We had a similar problem with a machine constantly jamming at the registration sensor. It turned out the black patch under the sensor was not black any more, it turned to a grey color, and machine thought it was seeing paper....the fix: a black permanent felt marker.