My pc wont turn on after i put a graphic card (tried 4870x2 and ati 4850) inside which consumes more power (10 20 W more) then the one im using right now. Ive tried everything, changed my PSU to 700w, changed ram, changed mobo, now im using a good 500w, but its not about my psu, i think the problem is related to my motherboard, but im not sure, im using a cheap mATX board.
Wait, it worked with a 4870x2? The 4870x2 eats way more power then the 5770. I would asume that its the card, defective card. Also make sure the power is plugged into the card. If it works with another ATI card, they I don't see why it would with another, unless the PSU is screwed, try a different 1 you can. rule that out of the way.
It didnt work with 4870x2 on my 700w, but my 5770 was working, i mean my pc turned on after i changed from 4870x2 to 5770 on my 700w psu, and 4870x2 i had was not false, cause someone else tried it in his pc and it was working fine. And i already changed my psu, and its the same thing.