My computer turns off completely when I put it into S3 sleep (like someone just pulled the plug).
It started when I upgraded my graphics card, have tried two different graphics cards, the strange thing though is it sleeps properly with the original graphics card.
I have an Asrock 970 Extreme4 AM3+ motherboard and here are the graphics cards I have used:
1) Sapphire Radeon HD 4850 (Sleep works)
2) Sapphire Radeon HD 4750 (Sleep doesn't work). Have put it in my son's computer and sleep works on his.
3) EVGA Geforce 570 (Sleep doesn't work).
Before you ask. Yes I have properly uninstalled and removed all traces of the previous graphics card each time.
Also, my computer works fine when the graphics cards are under full load, so I'm pretty sure that the power supply isn't at fault.
I am running Windows 7 Ultimate x64
This is a very strange problem and it's really bugging me, please help!