No PC recognizes it, impossible to charge through power.
 

A friend of mine, with my same nano clone (firmware 9.0.48 ) has a problem I've actually seen happened to some others:
after a couple of days, no PC/Laptop/whatsoever recognized it. It could still charge from them, but they didnt appear aware of the mp4 player player. Also, when charging it through normal power supply, it didnt charge, but it was like the player werent connected at all to anything.

How could he solve the problem? Also.... since it's not a firmware that can be extracted, is it possible to format the player somehow (not through a PC, of course) and install the firmware 9.0.43?