1. The power on/off is also controlled with the OS. Once you move to the new machine I'd use the restore CDs and take the offer for a total do over.

2. If that fails, try ikenfixit.com or notefix.com You can't get a firm price on these failures since some are simple 100 buck solder joint touchups and whatever dollars for shipping and sometimes it's a new motherboard for less than a thousand.

Sadly such failures are rarely fixed due to the ecomony of how cheap it is to use the USB device...