After working flawlessly for 18 months, I tried to power up my 4500S and got no response. This seemed to have coincided with a recent lightning storm so after trying all combos of cables, etc came to conclusion that the power supply was blown. So I ordered a new power supply and pulled the old unit out of it's slot, then just for the heck of it decided to power up again w/the power supply still connected but half out of the PC. The unit fired up, so I put it all back together, and (you guessed) nothing. So I took it all apart and had a repeat experience. Seems to me that something is just not making contact. Is there a logical way to trobleshoot this problem (other than just jiggling wires and reinserting the connectors)?