Problem solved, Thiago!!
I have a player like your ( an unbranded "like" Nano Pod, model number MS-818).
It was completly death after a wrong firmware upgrade!
Since it was not recognized by my PC, first I've opened the metallic cover,
and "5. Put device on recovery mode (short-circuit)" like explained in:
http://www.s1mp3.org/en/docs_deadrec...08b988899605d1
After I have used the "MP3 Player Upgrade Tool" (vers. 3.68 ) with this firmware update (thanx to Flashget and MP4PLY):
http://www.alexejw.net/firmware/MP-6...5.35%20full.7z
Completed this upgrade, the display of my player goes blue.
With "MP3 Player disk Tool" (vers. 3.68 ) perform a Format (in Quick mode) to the device.
After switch-off for two minutes.
Switch on.
Use "MP3 Player Upgrade Tool" (vers. 3.68 ) with this firmware update:
http://www.s1mp3.org/files/firmware/...Nano_1.5_C2.7z
Finished! At this point my player still go alive
Ciao
Max 8)