I reently built a PC for my friend but because of moeny restrictions we had to use some of my old parts. I used my old M2N32 - Sli Deluxe motherboard and my Antec TruPower Trio 550w. The problem is that whenever the GPU (HD4850) is plugged into the primary PCI-e slot the PC rarely boots. When it boots it is fine and tehre are no problems whatsoever. But this is very unreliable and seeing as my friend isn't very good with PC's he cant keep switching and fiddling with his PC. So when the card is in the Secondary PCI-e slot everything works apart from games, a bluscreen after around 3-30 minutes of gaming. No blue screen whatsoever no matter what CPU or RAM stress test so there is nothing wrong with them parts but anything 3D causes a crash instantly.
The strange thing is that I put my OLD Sapphire X1950Pro 512mb into his secondary PCI-e slot and everything works including games and there are NO problems or blue screens at all.
I was wondering if the secondary PCI-e slot can't be used for the full power of a HD4850 as normally the secondary slot is only using around half of the cards pwower because its made for SLi. It can't be the Graphics card because when the Primary slot works(very rarely) there are no problems with the HD4850.
Can someone give me advice. I don't want to advise him that its the Motherboard incase its the PSU seeing as he doesn't have alot of money
Thanks In Advance