So here's the story:
I recently purchased new computer parts and used a few older ones aswell.
Here's my computer part list.
-MSI 870-G45 AM3 AMD 770 ATX AMD Motherboard
-AMD Phenom II X4 945 Deneb 3.0ghz Quad Core Socket AM3 95w
-Thermaltake TR-550w Power Supply
-4GB Patriot Sector 5 DDR3 1333 (PC10666)
-250GB Seagat 7200RPM Hard Drive SATA
- Geforce 9500GT 512MB DDR3 Video Card (Gigabyte)
so what happened was i switched over to a Sapphire 4780HD 512MB DDR5 256 Bit video card, that requires two 6 pin connectors. I hooked it up to my power supply which has the two six pin connectors and i had three red lights come up. No picture showed, no lights on the keyboard, no boot screen at all. I then put my 9500GT back in, which was working perfectly fine. Unfortunately, nothing booted up. I tried a different PSU with both video cards which previously ran it, and nothing would work at all. So now im unsure what has happened, i believe my motherboard may be shot now.