DP-770 on CS2551ci Unresponsive

[JR Skewing]

My client has a CS2551ci with a DP-770 that won't run. The 'Doc Loaded' LED remains off.
Using Sim U244 the ADF sensors check OK (I wasn't able to check: Timing - Tray - Lift U-Limit - Lift L-Limit).
Using Sim U243 no motors or solenoids actuate.
The manual isn't clear (to me) as to the source of 24vdc on this critter.
Any thoughts?
TIA!
...Lorenzo

[lees]

I have seen this on a couple of machines where nothing seems to work. There is a sensor that is actuated by the reading guide (the white strip on the DP that sits over the slit glass when the feeder is down against the glass). The actuator for this sensor is on the reading guide, but the sensor sits above the reading guide attached to the DP. When the DP is in the down position, it pushes the reading guide up to actuate the sensor so the machine knows that the DP is in the down position and ready to feed originals. I have seen the actuator on the reading guide bent out of place or broken (don't know how that can happen). I have also seen the sensor loose in the holder. Remove the reading guide and check the actuator on the front of the guide. Also make sure the sensor is clipped in the holder like it should be and being actuated as if should. You can check this sensor on some machines using maintenance mode 244. I can't remember what the sensor is called in U243. The smaller MFP's do not have maintenance mode 244. Hope this helps you get started.

[Santander]

You have either a bad original detection sensor or more likely the flag that is part of the plastic holder that houses the pickup roller and feed belt is not activating the sensor due to the holder being cracked.

[eddie110171]

Did you run a U906 to see if anything is disabled? I always do it before I look at anything else and then start trouble shooting. The DP will get disabled if the lift plate gets stuck on a paper clip or something.