ive opened up my sandisk sansa to find the right side of the processor getting quite hot
the device dose boot but shuts down when the processor starts getting hot. it starts runs for one second the hangs then just looses power. when it hangs the battery just drops 5 percent (like 88 , 87 , 86 ...) usb power and using stock firmware is a similar story
I charged it with a cheap car charger and the case was quite hot so maybe a solder bridge formed?
the charging circuit components looks un damaged and there wasn't any smoke