HP Color LaserJet Pro MFP M477fnw - Rear Door Open

Apr 5, 2020
My display always says "Rear Door Open" even though the door is closed.

I opened the printer and investigated it in the rear. My understanding is that there is sensor with three violet cables. If the door is closed there is a black plastic part which is moved in between the sensor. (I was able to first remove the long black plastic with the sensor and the I removed the sensor from the long black plastic. Finally I put everything back together.

How does the sensor actually work? There seems to be only a black plastic which comes in between.

What is the purpose of the metal wire making a rectangular path?

Is this the only sensor or are there more sensors?

Is it likely that the sensor is broken and can I get a replacement part, or do you know of a workaround to basically short the sensor so that the printer always thinks that the the door is closed.

Below two pictures. The sensor is in the middle of the second picture. The first picture is a larger view with the sensor in the middle upper half.

Thank you!

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