Hi I got the the sapphire 7970 vapor x last month install it worked fine but soon as i installed the driver's after 10 min or so i got a black screen saying no signal, so thinking it was a psu issue I bought a new one today installed the gpu works fine but soon ad i installed the drivers again i got a black screen (no signal) but when drivers aint installed i dont so was wondering if anyone has had this problem before and knows how to fix it thanks.