There is no obvious defect that I could post photos of. The whole device got bent a little so that the screen unit jumped off its rails, ripping off the flex cable in the process, I guess.

The screen looks OK from both sides, but when I now switch the device on it stays completely black.

The vibration I reported above happens when I plug in the USB charger or attach the device to a computer. In the latter case I can access MyDocs just fine. I can only stop the vibration by removing the battery.

Switching the device on without USB cable attached doesn't show any obvious signs of life other than the indicator LED glowing white when pressing the power key, just as it should. (So at least the new cable is working properly. )

I'll try to attach a screen unit from another device and report back.