I am fixing a computer for a friend. Every time I plug in a CD drive, and I have tried 3 different ones, the computer shuts down. I even tried to unplug the harddrive's cords and using them to plug in the CD drive. The "information strip" (I will call it that for I don't know it's real name. But it's the flat strip with the black square at the end) plugs in fine but the instant I plug in the "power cord" (the little white square at the end of the white, yellow, and black cords) the computer immediately shuts off. It won't start back up until I unplug the main power source and plug it back in. The main power source is the box inside where all those cords come out of. What could be causing this? The fan works, the computer comes on and works fine, but if she puts in a cd, the computer shuts down. When I try to install a new cd drive it also shuts down. Any ideas?

The computer is a small HP desktop. HP Pavilion xt973

You should not be plugging/unplugging wires while the computer is running. You could really mess something up by doing that. Plug in the drive when it is powered down and then try to turn it on. Second, do you have a known good power supply that you can substitute?

I know. But it doesn't come on at all when the drive is plugged in. So I unplugged it, powered it on, then put the power cord to the drive and it instantly cuts off. To your last statement, yes. I took her original one out and put in one from another computer. It powers everything except the drive. It baffles me. 2 different power sources and 3 different cd drives with the same results. It's not the information strip. It's something to do with the power cord and cd drive connection. Even when the info strip isn't connected, when I connect the power cord, it cuts off.

First off don't ever plug/unplug anything from the inside of the computer while it is on. It isn't safe for you and it isn't safe for the computer. End of discussion.

If you are trying different PSUs and different drives with the same result that pretty much rules out everything but the motherboard itself. One thing you need to make sure of is that you have all of the power cables connected to the motherboard. There should be 2. One is the main one with either 20 or 24 pins and the other has I believe 4 or 6. Sometimes the small one is overlooked. Make sure that it is plugged in because the motherboard won't get enough power without it. It is not the same one that plugs into the cd and hard drives. If you do have that properly connected then I'm afraid that the motherboard is quite possibly damaged provided that the PSUs are adequately powered.