Mr.tadad1,As seen from the pictures in row2.the right hand side represents the bad one,whereas the left handside represents the better one. However,these 2 mp4 players use the different versions of firmware. the good one is "SC85051C" and the bad one version is "SC85051F"--I did try using the "SC85051C"version into the bad mp4 one and it's invalid(no response at all). In other word,i can't put the firmware of the right hand side mp4 into the left one.