Mid 2010 white Macbook unibody turns off when certain keys are pressed on keyboard.

I have a mid 2010 white unibody Macbook laptop. Seems to run perfectly fine but there seems to be some kind of short or something in the keyboard or motherboard. Some keys respond and other keys don't respond at all but some keys on the keyboard, when pressed, cause the entire computer to immediately shut down. Any idea what might be causing this? Should I replace the keyboard or might I need a new motherboard and keyboard? I've tried a complete software wipe with restore and a wipe without restore. All software and firmware up to date also. Looking into this for a friend. No known liquid damage. Possibly heat damage, he said it's been constantly left on a towel/blanket where little to no ventilation for fan is available. Thanks in advance!