You still haven't convinced me that you have eliminated the power brick as the culprit. If you are synching, then I am assuming you are on mains (AC) power. The wall-wart types, rather than the power brick types, occasionally go on the fritz. A brief power up then instant death could be a broken thermal fuse in the power pack, not the player. I know it died in the car also, but you may just be doubly-unlucky with coincidental bad wiring. You should try a loaner PSU and see the effect before despatching the player to Cambridge.