Passed through this thread several times... but really have no ideas. My initial impression is that it is a hardware issue. If that is the case there is not much that can be done on this end. Does not hurt to try.
Unless you enabled USB debugging before the phone went dead, the PC utilities you have will not really be useful.
Have you tried booting the phone without the SDCard installed?
Can you still get to Hboot? If not, try removing the battery for 20 seconds and putting it back in. After you put it back in press the volume button down and press power.
If you can get into HBoot we would have to find the RUU image for your phone.