f.9torres, It may be dead for good, I have one player that is the same, shows no signs of life at all. The only other possiblity is to use a JD-ICE device to hard flash the firmware directly to the chip. Not something I have tried but if you have any electronic knowledge may be a good project. You can find some info here:
http://wiki.s1mp3.org/index.php/ICE_how_to