Thinkpad T42 will only work with battery


Jun 6, 2012
I have an IBM ThinkPad T42 (well my mother's actually) and recently my mother spilt coffee on it. After letting it dry for a few days I noticed that some keys on the keyboard didn't function so I replaced the keyboard. Up until here everything was fine. Now the laptop randomly shuts off asif it has lost all power, although I have noticed that if the laptop is running on battery everything is fine. If the laptop is running with an AC cord plugged in with no battery it will work between not at all and 5 mins, if the laptop is running on battery it will run for aslong as the battery lasts, and around a min after I attempt to charge with the AC cable it will shut off.

Any ideas? I don't really want to have to purchase a new motherboard but it is an option if nothing else is available.