We would need to know the nature of the PC failure. The only component of
the PC that could possibly fail due to a mains power problem is the power
supply, because its output is regulated -- it either outputs the right
voltages at full current, or shuts itself off completely.

It might over-exert itself stepping up a lower-than-normal input voltage...

Also, power cutting on and off repeatedly (a lot of "flickering") might
damage the power supply or even, I suppose, a disk drive or something. Did
that happen?