You did the paper clip trick and it turned on and then off? Did you have any load on it like a case fan? If you did and it turned off like that then its a PSU issue and its time for an RMA.
The paper clip caused it to turn on just long enough to cause its fan to rotate about 180 degrees. There was no load on the PSU at this time.
Strange how letting it rest for an hour or so allows it to reset. Must be a temperature issue?