to be clear, did your player look like this when it was working??
did you make a backup of the firmware?
when you tried to load setup.rkw file, what file/firmware was that??
if it is like the player in the image, i have that exact one and also suffered a loss of partition for no reason at all, just died through normal use
i used the rk27dm tool, the R button did not light up for me so i pressed the U button
this appeared to fail .. but when i reconnected the player to windows xp, xp saw a new drive and asked for drivers, i pointed it to the drivers, not let it go by itself, it installed and i had my partition, it needed formatting and then all was OK