It may be screwed up. For now, to deal with it set the power balance the same for AC and battery and see what happens.

Almost all laptops dim the display and change the processor mode from performance on AC to economy on battery. This is the main thing that could be freezing the OS. If it was rebooting, shutting down or something then that would be different. It is looking for a power configuration that is likely not there.

On mine I can control it from Windows, but not all machines will have that and if you reload or reset stuff, this config data coulld be missing or corrupt. It can be in BIOS or the OS, or both. (kinda like control panel)

Go back into setup, find power management. If you can find in there ANYWHERE that differentiates between battery power and AC, set them identical. Or turn the whole feature clean off if possible.

Incidentally, before proceeding, will it boot up from AC power ? If so, does DISconnecting the AC power cause this as well ? If not, you set everything to run as if it on batteries all the time. In fact that is probably best anyway, unless it dims the screen and makes it hard to see. I only run mine on battery in the dark because otherwise it is too hard to see.

Hell, I guess a solar battery for it would just about fix me up woulntit.