Thanks for your help - I took off the cover today so I could see what was happening inside the computer once I turned it on and I'll detail it as best I can. When it is turned on, the front LED lights start flashing (in a continuous on and off pattern). I could see that the fan was trying to turn although it too was struggling (the blades wouldn't actually turn but sort of moved back and forth). From the way the lights and the fan were acting it seemed like power was going on and off. Nothing else was on - definitely not the HD nor the CD and the monitor just had the No Signal Input message. This all continued for approx 5 minutes with absolutely no sound coming from anywhere in the computer. Then that strange thumping sound came from the speakers lasting approx 1 min and increasing in loudness (fan was still struggling and lights were still just flashing while the noise was on). I tried to see if it was the HD or anything else inside the computer making the noise but it only seemed to be coming from the speakers. Anyway, as soon as the thumping sound subsided the fan and the HD both kicked on, the LED lights were now steady and POST screen came on. From then on it was as if nothing had happened, the computer worked fine, no crashes, no slow downs. This same exact procedure has been going on for about a week except it's taking longer for the computer to kick on (it used to be 1-2 minutes and now it's more like 5 min.). Once it kicks on, though, the computer works just fine. I'm really thinking it's the power supply dying but I've never had one die before so I can't be sure. Does anyone agree with this? Also, assuming that it is the power supply - this is an old HP Pavilion with a 110W power supply (it's really just a spare computer, but one I need to keep), would I have to replace it with the same wattage or can I go higher? What would determine the power supply wattage I can use? Don't know if it helps, but the motherboard is an ASUS DB98XV (originally put in by HP). Again, thanks for any help!