I have just recivered my MP4 player (very old one ... 2005 Onda clone!).
I'm so happy ....
I did the procedure in this page
How to: Recover a dead MP3/MP4 player
and I used a full firmware in annex (.bin)
Step 1 : I touched only the 1st or / and 2nd pins of NAND flash memory (the pins are so small so I don't know exactly)
see
S1mp3.org - Firmware replacement for s1 mp3 player - Dead recovery guide
upload the generic full firmware: explorer can see the 2 partions of removable disk (but they were 0 KB!!!)
step 2 : I touched only the 1st or / and 2nd pins of NAND flash memory
upload the right old firmware (.fw file in annex)
I would like to try to modify my firmware .... but i think I won't touch my MP4 player nevermore!
bye