While recently trying to install a second hard drive (WD800JB), I opened the case and slide the hard drive into place. This required unplugging several IDE cables and then plugging them back in (to make room). I also unplugged the power supply to the floppy, but plugged that in afterwards as well. When I was taking the case off, I took out one screw to the power supply on accident because it was located directly next to the case screw (wierd Compaq design). I screwed it back in when I saw the power supply move a bit, this put the power supply back into its origional location. Anyway, I realized I needed to check in my BIOS if the origional hard drive (Matrox 30MB) was slave or master. I plugged the whole computer back in, case off, and hit the power on button. Nothing happened. I tried the button a bunch of times, nothing happened. Power to printer and monitor was good so I knew that it wasnt the outlet. The connection between the switch board and motherboard was fine. Connection between all the drives and power supply seems fine. I took the second hard drive completely out, through the front this time, as not to interfere with IDE cables again. I unscrewed the power supply completely, then made sure it was aligned properly and screwed it back in. Still no boot. No traces of power at all, the cooling fan doesnt even do the spin for 2 seconds thing it always did whenever I plugged it in. Apparently I have a problem, yet no solution. Did I fry the power supply? Did I sever a connection somewhere? Was it idiotic of me to have messed with the IDE cables? Please help, much appreciated.

Hi Sewan. I know this is far too obvious, but did you check the power on/off switch on the power supply itself? You may have accidentally bumped it while opening the case. I have done that before, is why I ask. Aside from that, try removing the drive ribbon cables and power cables, to see if it will start to power up. It's possible to get one of the ribbon cables in backwards. The red or black thread on these go to pin 1 on the drives. I'll leave it to you to determine where pin one is on each drive. It is USUALLY the one nearest the power socket, but don't quote me. I doubt that you have permanently harmed anything, unless there was a static discharge somewhere. You did use a static strap, right? Or, at least discharge yourself by touching the metal case. I hope this helps you, and good luck. Let us know here how it goes. :)

I truely mean not to insult but did you plug the power cord back into the power supply? Bryan

Well if u unplugged the power supply from the motherboard. If u did and it is ATX(which im sure it is as long as it isnt like 8 years old) it will not turn on anything. or it u accidently forgot to plug the power switch into the motherboard it wont tunr on. it it is AT(before ATX) and u didnt have it plugged into the motherboard u will still hear the hard drives spinning but nothing will apear on your screen and u wont hear andy beeps. I hope this helped u. So just check all your connections. And buy the way there shouldnt be any problems that happened from disconecting your IDE cables as long as u hook them up so the primary channal is hooked up to the same drives and same with the secondary channel.

I figured out my problem, it was not the power switch at all. I took the machine to a shop where they tested the switch, and it was fine. Turns out it was the power supply that was dead. Had to pick up a new one. We figured it was the power supply if it wasnt the on switch, since everything else was plugged in and set up properly. Basically it was one bug coincedince that the power supply crapped out right after I put the hard drive in. All better now, thanks for help. If you ever have to deal with getting parts or service from compaq, good luck. Their phone service and internet site were looped mazes leading me nowhere, and the registered compaq service center in my area actually told me they wouldnt help me because I had presario and Compaq no longer supports presario. Good one! In the end the most helpful people were the guys at the electronics shop where I tested the on switch and purchased my new power supply. I will never support compaq again. Remember to support the little guy, buy all your parts from a local shop and have them help you build your own custom machine rather than the crap and major manufacturer just throws into a case.