where can I get the firmware for my mp3/mp4 player?

Well I got a 'cheap-o' from Japan on EBay and am having an issue.
When I loaded it with music then tried to play them, it only played 8 songs over and over. It would not play any of the others though it did show they were in there. So, Now it wont even show there is anything in it. ('File Error') I might have erased the firmware when I formatted it... Any ideas of where to start? The manual that came with it is in really bad 'Chinglish' and makes no sense at all.
Under properties, it says: 'AMT_MP3' then 'WDC WD1600JS5 NCB2'. Is there somewhere to get and reinstall the firmware for it?

Thank you in advance!