help with mp4 player

i`ve got an mp4 player h85 mtv v2
with firmware 3.2.08
it was working really good i changed the firmware into v3 it worked fine,but the after a few days it just stopped working and wouldnt go on,i tried the screw driver trick while it was plugged on the pc,it worked but every time u have to put it on this way.what should i do?