Powers up but never finishes loading XP before goes blank

[kam31uf]

I recently installed a new graphics card, upgraded to XP, and installed a new HD to my computer. Then I transferred some files from my old HD to the new one. Everything was working perfectly. Then I took the computer home from my mom's house and on the way home the CPU slid from one side of the car to the other hitting the door. Got home connected everything and started it up. Everything was fine I signed in to the desktop and was getting ready to open a program when the screen went black. THe power was still on but there weren't any lights on the front of the cpu. I had to hold in the button to shut it down. Then I tried again...7 more times... and each time it would power up and go through the 1st startup screen and the 2nd, but then it would do the same thing. The fan always runs and I took the cover off to see if anything had come loose. One of the black and white wires(that leads to the power button) was loose so I pushed it back in. Still nothing. PLease if anyone has a clue that would be super.

So far this is what I have tried to no avail:

1. Everything has been checked for connectivity, and all was connected correctly. I pulled and put back in the memory and graphics card, the cpu is connected to the mother board. Tried starting it after that and got the same thing. THen I pulled the data and power to the drives and started it, got this msg: Disk Boot Failure, Insert system disk and press enter.

2. I unplugged the power and data from the HD, inserted the win 98 startup disk in the connected floppy drive and started it up. Got this same msg: : Disk Boot Failure, Insert system disk and press enter.

3. I checked the bios and made the floppy 1st, the cd rom 2nd. I retried the win 98 startup disk and got the same msg. realizing I should unplug the cdroms I unplugged them. put disk in and started up. The floppy light stayed on from when I turned it on until I turned it off. I could hear it running the whole time, I got the same msg as before.

5. Realizing the data cable was in wrong, I Swapped the cable end on the floppy and tried again. that worked - I got the win 98 options to startup -
So then I started it up with the HD plugged in and it only got to the 1st regular startup screen before it went black. I never got to the 2nd screen.

6. I tried starting in safe mode with the floppy and HD in first and it only got to the 1st start up screen. Never saw a safe mode option screen. So I unplugged the floppy since it seems that caused the 2nd startup screen to disappeared as earlier noted. Started it up got to the 2nd startup screen and pressed F8. There were so many choices so I chose plain old safe mode. Then the screen went blank again....

7. also confirmed that VGA start up doesnt work, still goes blank.

I am open to ALL suggestions, this is SO very important that I get this working.

[ccb056]

Take the heat sink off the cpu, reseat the cpu, reseat the heatsink.

The heatsink probably broke contact with the cpu and it is overheating.