I have a Sony NWZ-B133F walkman MP3 player.

Its always worked fine. Then today I plugged it into PC to charge, then later put the PC to sleep without removing it. When I restarted the PC it said USB device has malfunctioned.

I removed it, pressed some buttons, and nothing. Pushed reset and still nothing. I upgraded the firmware successfully from 1.0 to 1.01. It then roared into life while doing so plugged into the PC. At this stage the screen is doing what it should, PC sees it, I can play music from it, but as soon as I remove - dead again, and upon plugging back into PC splash screen comes up Sony walkman, but thats all.

This has been my favourite MP3 player, and I want to get it going again.

Whats the next step?