A some time ago by mistake upload in my S1MP3 wrong FW.
My board ID "MP-683EGCFMV1 MAIN 05/09/09", but I upload fom file "MP-683EGCFMV1 MAIN 05-05-09 ATJ2051 (FULL).bin" (Mistake i one digit ).
As result player not turn on and in "ADFU mode" (when connected to PC).
First problem - I don't have a FULL image of original firmware.
The second (I think most big) problem - when try to upload firmware again (by "MP3 Player Update Tool" the same file width FULL image) progress bar showing approx. 50%, then pause 30-40 sec. and error message "Read or write device information failed! Please exit the program and check if device is connecting!".
Maybe it's hardware problem (width NAND flash)?