computer wont turn on with video card?

Question

today i got on my computer for like 10 min then it froze. (this usually happend for the past 6 months so i press the power button on my comp to turn it off then back on again, since alt+ctrl+del+del usually doesnt work.) but today i did all that, exept my comp turned on for a split second then off, i pressed again there was nothing. so i checked everything, cleared my cmos.. but when i took out my video cards the power worked. when i put them in the comp, it lits up split sec then off. i tried putting my cards 1 at a time, did the same thing. dint try switching them places because theyre connected with water cooling.

this is my 2 prob with my comp, first 1 was my comp didnt turn on at all cuz burned power supply (i had 850w, now i bought thermaltake 1kilowat)

my video & mobo are:
2 bfg 7800 gtx 256
asus a8n32 sli deluxe

Answer 1

It looks like your video card is overloading (shorting) the +12V rail that is why power supply is enabling auto-shutdown (a safety feature of all PSU). Check the cards for bloated caps, burn marks on the pins and on the power connector. If everything checks out ok, try booting with power connector of card not connected. There will be no display but observe the fans to see if PSU will still go on auto shutdown:
1. If it does NOT, video card could be fried and has a short.
2. If it still goes on auto shutdown, the short could be on the pins connecting to the PCIe slot.

Answer 2

300 to 400 Watts should be plenty enough if you have Thermaltake or any other good name brand.
You say you had a burned power supply and now your graphics card shuts your computer down instead of powering up?
I would suggest that either your graphic card and RAM card contacts may be scored a bit from arcing, due to low or high power surge while your power supply was failing.
Take those cards out and take a hard white eraser and clean the contacts until you are satisfied that any corrosion is gone.
Now, put them back in and try to run your unit.
If this didn't work, your problem may be that your old power supply has shorted one or both of these items.
Normally the RAM is more protected, so I would try the graphics card first.
You may also have a DirectX problem and might be able to repair that problem by booting up in safe mode and using the Help and Support section to troubleshoot your Games, Video and Sound Devices.
I have included a site which has a tricks and tips page that offers a free approved, diagnostics/repair cd download you can try if you can get online to burn it.