Second model sent to me has stopped working. On this occassion it seems nearly entirely dead. No movement. No Beeps. One ssingle green constant light. PC also no longer detects it via USB.

There seems to be a lot of heat generated. The black pastic stuff around connections has started to melt in places.

Can anyone advise me on what I could check with a Multimeter to try and isolate what needs replaced. Or is the whole board fried?

What would have caused it?

Furious. This is a replacement model. Both went bad with very little usage.