How to fix my Display Graphics Driver?

My Laptop, Lenovo Y460 with ATI mobility radeon 5650 has display driver issues. Running on Win 7 64bit, installed manufacturers specific display driver… Fails on boot. Official and latest ATI Catalyst and yet still having BSOD on boot. Standard VGA works when in Discrete graphics mode but when switch to official driver, it crashes. Intel GMA works but I still need to use the separate GPU. Is my GPU fried or are there other things I can do to fix? Is there any shop in SG that fix laptop GPU?