PC wont start after vid card + PSU upgrade

Motherboard: Gigabyte GA-78GM-S2H
Processor: AMD X2 4850e
Memory: 4x1GB Crucial Ballistix 800MHz (6400?)
PSU: some no name came with the no name case I'm using
Hard drive: 500gb WD
OS: Windows XP SP3

So my computer was working just fine. I decided to upgrade my graphics from the integrated ATI HD3200 to an nVidia 9800 GTX. Before I could do that, I needed a better power supply. So I picked up a Corsair TX750 (Yes, I know 750 is complete overkill but that's besides the point).

I uninstall my graphics drivers, restart my computer. Everything is still working fine, except for the horrible graphics.
Turned my computer off, put in the new PSU and video card.
Turned computer on, passes POST (single beep) but then freezes on the first screen that usually comes up that has the energy star logo on it and stuff.
Turn computer off, then on...nothing (not even POST). Turn it off and on again......still nothing.
Took out the video card but left new PSU in...same thing, passes POST but freezes on first screen but then won't even go to POST.
I put the old PSU back in, still the same thing, POSTs then freezes then wont even POST.

It seems like if i let it sit for a little while it'll POST one time but then freeze right after then not do anything until the next time it's left alone for a little while again. Maybe something to do with cooling down???

Now I'm stuck, please help.

I already checked the connections a million times, CPU 4 pin is hooked up, motherboard 24 pin is hooked up.
Tried removing some/all the memory sticks, no difference.
Tried disconnecting the hard drive...no difference...same problem. (actually its weird it actually POSTed with no hard drive one time)
Oh and everytime I try to turn it on, all the fans and lights come on just fine.

Any suggestions? My next plan of attack was going to be to order a new processor :(
6 answers Last reply
More about wont start card upgrade
  1. Did you plug the power to the graphic card? Dual six pin PCI-e? (Or single if you have the newer revision)
  2. Our standard checklist and troubleshooting thread:

    And the included breadboarding thread:

    where I talk about building and testing in stages.
  3. Yes, I plugged in the pcie power cable for the vid card (only one). But I've since taken the video card out and went back to the integrated video to try to make it work again but it's still not working. I'll try the bread boarding thing again I guess. That's basically what I did but with everything still in the case.

    If, with everything disconnected except cpu and hsf, it still only POSTs one time then not at all, would you guys say its the processor or the motherboard? If I remember correctly, this motherboard supports AM3 so maybe I can get a newer processor but if I have to replace the motherboard then I guess I'll get basically a whole new computer lol...

    Thanks for the help guys. I appreciate it.
  4. If you put the old PSU back in the system, will it boot properly?
  5. Well I must've been doing something wrong last night because I followed the bread boarding thing and it's working just fine! :bounce:

    The cd drive was connected to the motherboard last night, but I had forget to give it power, could that have caused issues?? Anyway, I'm using the PC in question to make this post. Currently using the new power supply, still havent tried to put the new vid card in again. What's weird is that the old drivers somehow are back because my video quality is just like it was before i uninstalled the driver's.

    I'm gonna try to get the new vid card working now, I'll post up how it goes.

    Most importantly, THANK YOU!
  6. Installed vid card and drivers, everything seems good. Tried it out on All Points Bulletin (new MMO) and system handles it just fine. Thanks again everyone.
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