Laptop won't charge when turned on

[Goodonebales]

Hey, guys, my brother-in-law just presented me with an interesting question. When his laptop is turned on, the AC Power Supply doesn't work. It only charges when the laptop's off. Unfortunately, though, his battery's also shot, so it only stays charged for about 20 minutes. He doesn't really carry it around at all, so he really just wants it to work when plugged in. Any ideas if the problem lies in the battery, the AC adapter, or neither? Or both? Thanks.

 

[Alvin.C]

Hello,

What laptop does he have? And how old is it?

Also, if you remove the battery from the laptop and plug up the power adapter, does the laptop power on then?