mmp3642A help.

Yo my friends got an mmp3642A mp3 player, we can transfer songs to it fine since we can put it in the usb and look and / play the songs *from the computer* that are on it. But when we try to turn it one when its not plugged in it just goes to the memorex screen then turns off, then just keeps restarting itself. I tried updating the firmware but then it says to put the mp3 player into system recovery mode but idk how and the memorex directions are like cut off on there website, so does anyone know wats wrong with it better yet how to fix it.