Compaq desktop problems

O.K. First of all I need to say that this was a Compaq Presario SR1303WM computer. What I mean by that is that I replaced the mother board because it was faulty (least I think that was the problem LOL). I have herd that changing the MoBo will prevent Windows from working right but I have a problem before I even get to that point. It started as I moved my MoBo to another case (put it together on cardboard to prevent any shorting to see if it would work) it wouldn't boot. it worked fine before hand but my father needed the case for himself because he didn't wanna buy another. As was stated the PC stopped working right after removing the MoBo from the case. I did some trouble shooting on the net about how to check this and that and the other thing and determined that the MoBo was faulty due to the CPU heatsink getting warm after it had been turned on for a little bit. So I got a ASRock K7NF2-RAID Mobo put it in the case with a different power supply (Compaq uses weird PSUs from what I understand and didn't wanna short or fry anything) Tried starting the PC and I get nothing but a black screen. This is my config:

ASRock K7NF2-RAID Motherboard
AMD Sempron 3000+ (Socket A or Socket 462)
512 MB of Mushkin Enhanced DDR PC3200 ram (two 1Gig sticks waiting to install after Fix)
ATI X1300 w/256mb ram (PCI bus)
Segate 40 GB HDD (IDE)
Windows XP Home (from Compaq) **Have XP Pro and/or Win 7 ready for install**
Lite-On DVD-RW
Rhycom 450w PSU: some specs follow though I have no idea what they mean:
+5V=35A
+12V=15A
+3.3V=26A

This is what it does in detail:
1) When the PSU switch is turned on it turns on immediately without the power button being pressed.
2) Even without power (cable un/plugged) the monitor will turn on and say "No signal. Check Video Cable." when I connect the monitor (not sure if this is normal)
3) When the power is on the HDD light will stay on constantly for roughly 30 seconds the turn off (32.73 seconds according to stop watch give or take a few milliseconds)
4) The power light will constantly stay on (so i don;t think the PSU is the problem, let me know if you think otherwise)
5) To turn the PC off I have to hold the power button for 4 secs or flip the switch on the PSU. (reset button also works to reset)
6) The DVD drive winds up like it's starting. DVD drive will open and when a disk is inserted it will spin and the light flashes like it is reading.

Some of the things I have done to try and find out what the problem is:
A) Tested HDD in another PC. HDD can be completely accessed and has no errors in testing.
B) Checked all jumpers and made sure they were set to the proper settings (FSB Jumpers set to 166, no multiplier jumpers)
C) Checked Video car in another PC (it works)
D) Put another Video card (PCI) in the PC (Same results)**I dont have a AGP card to test at the moment)
E) Set and Reset Ram and CPU to make sure they were properly seated
F) Made sure that all cables were connected properly
G) Made sure all drive (HDD/DVD) jumpers were set properly. (Master/slave)

I know there are probably other things that I did that I didn't list but can't remember them at the moment. This is not even close to my first PC build/transfer so I have some knowledge of things and how they are supposed to be so don't be afraid to use some tech speak =) hehe. oh I also do not have a PS2 keyboard or mouse to use to try and blindly do something in the Bios unless a USB one will work without it being installed. If there is anything anyone on here can help me with it would be GREATLY appreciated. Thanks for taking the time to read this book. Sorry it was so long just wanted to get as much info out on it as I could. Thanks in advance.

hi gnomey , see if you can go in to the bios and look for manufacture setting click on it
and restore manufacture settings , once you do that restart the pc and see if everything works , you might be losing the drivers from it , but that is not a problem , hp compaq have the drivers on line where you can down load them
and put them on cd and reinstall them on your pc , wish you all the best here is the link from compaq


www.compaq.com
go to support , type your brand name with model number in and click search , when you get a page open select it for windows xp and click next
you will see all the drivers from that pc there , ok good luck buddy take care