Black screen on Dell Inspiron 1501 on AC Power

[FighterPilot]

My friend has a Dell Inspiron 1501 that works fine on Battery Pwr but when you plug in the AC charger to run it, the screen goes black with no warning. Unplugging the AC pwr does not return the screen. He must reboot the computer to get it back up. Any ideas on what could be causing? We have checked all the power settings and sleep settings and everything seems to be fine. Help!

 

[Tmagic650]

Try another AC adapter