Okay, I had the same problem, but my friend told me what I could do and suprise suprise it fucking worked O.o
You got to bind a towel around it so that it cannot cool down (close the cooler exit) Then you turn it on and wait until it overheats, it will shutdown itself when it does. When you have done that it should be running again. It sounds fucked up but it works! Atleast for some weeks
I've done it 4 times this far
Sorry for my English ^_^