Chinese MP4 help!!??

I bought this MP4 player from EBay. It worked fine for a few months, now it says there is a format error? Any help would be appreciated

Please send me FIRMWARE FOR
LG MP3 B803 CM50012 ACT_V9.0.50

Thank You.
Carol

I WANT TO UPGRADE MY LG MP3 PLAYER QY-781FV2CM70038 2007/12/04 ACT_V9.1.52

I have a mp4 and i got a problem that it doesn’t open but stays only in the loading screen.
How can i use it so i can listen the music in it.
also it is not shown in my computer as a usb drive

my mp4 not recognized in my pc Solve when i plug my sony mp4 to my computer by usb port my windows shows that device not... (More) when i plug my sony mp4 to my computer by usb port my windows shows that device not recognized.plz....help me with this.....