Just few days ago my GT 630 broke down. I Changed my motherboard's southbridge thermal paste and i put my computer back on and when i turned it on, it loaded windows and then came black screen and it does it everytime. I'm gonna take it to the warranty.
At least i can use my computer, i have currently msi 7300 gs 256mb and it's flashed(or something like that) to 7500 le from rivatuner. I overclocked it pretty much,and i gets like really hot. I cleaned it from dust and changed thermal paste.