C450 doc feeder

[tech51]

Hi all, has anyone had this fault? When the machine is powered up or wakes up from sleep, the doc feeder indicates a jam under the middle cover. When the jam is reset by lifting and lowering the cover, the doc feeder and main body work normally until it goes back to sleep. There are no jams logged in the data collection and even when it says its jammed the sensors all check out OK in sensor check mode. I've cleaned the sensors and beltanyway.
Can anyone help? Thanks in advance.

[minimerlin]

Seen this a few times ..check the sensors in turnover area are fully clean, the do a sensor initialisation and recalibrate, if you get any NG that is the dirty sensor. All is fine if you get OKs on them.