另外可能是 power adapter.

是不是機器隻能run low power mode (600MHz)? complain not a dell adapter by your laptop when you boot (with the adapter on)? Dell adapter has a center pin that's believed to be a data line, where the laptop will communicate with the power adapter, if not "dell" (or the power adapter id unit fails), the machine won't charge and won't run fast mode. Check bios, there maybe something called "enable/diabable adapter identification"-something like that.