|So, is formatting the one hard drive your current goal?|
I had a similar problem and found that a couple of the motherboard capacitors were shot. Sometimes it would boot up and for no apparent reason it would just shut down. Upon restarting I would experience the exact same symptoms you have described.
The capacitors, on the motherboard, have an "X" etched into their tops. If that X is bulging upward or the base of the capacitor is bulged or crap is oozing out of the bottom of it then...
Otherwise, why can you not format or fdsik the one that does boot up? What is stopping you from performing the task?