New video card, perhaps? Does the computer power-up, and you just can't see it? Any beeps? etc.
also, fpsmitch, it COULD be a hard drive issue, but it is somewhat improbable- she had it connected to a surge suppressor, and even if something were to get past the surge suppressor, the PC power supply is designed to sacrifice itself if necessary. Also, even if the drive got a surge, the data would not suddenly "wipe" the drive. (unless for some stupid reason the manufacturer decided that whenever voltages went outside necessary limits, that the HD would consciously wipe itself. The Controller, however, could be damaged, thus causing all data to be inaccessible... if that were the case, however, the computer would still start up and be visible, just with a "missing operating system" or similar error.
Also, I'm curious- if you can't see anything on the screen, how do you know the mouse doesn't work? If you had an optical mouse and the mouse's red-eye is off.... that is NOT a good sign at all. Either the USB hub was severely damaged- or, more likely the motherboard was fried.