RCA H106A 5.? G music player (by 2 users)

I have this thing for a year. I recently borrowed a USB cable to charge it cuz the original one was misfiled. I was using Windows Media Player v 11.0 to synch it and it was fine. Recently it started failing to recognize the device when I plugged in and synchs were failing on just a few tracks saying the device was busy or something but I could replug a few times or try the synch again and it worked so I was blaming the cable. So I was using it with a fully charged battery and it just plain stopped. I can see dimly the screen for the last track I was playing. I couldn't shut it down. Yes I messed with the lock switch. I tried everything so I just left it overnight. Nothing respond when I replug it into the computer. Whoa all of a sudden it's now saying charging. But I think these problems will repeat. I will wait until (if ) it charges back up. what is causing this freeze? This is a POS I shoulda sprung for an ipod.