Hey! sorry for the delay... only now I just checked my mail and noticed you rated the best answer. I never had the thread highlighting and it's not the only time... forum errors for sure.
1. Which wires were backwards, 4/8 pin or 24 pin?...
2. and you mean no video signal (blank screen)?
3. Does it beep, more than one beep, or nothing; a few seconds after you press the power button?.