Any idea what could be the possible issue & how to resolve it

??
yr gfx card overheatin or 1/2 uplorry lioa
as mentioned b4
since u got nothin to loss
sprayed WD40 into the graphic card and the teeths...
leaved it for a couple of hours in the open air envoiroment
than used a copperwire brush(buy from hardware diy shops)
rubbed every parts of the gfx card hard
placed back..if its worked(most probadly for the next few months)
u r done
part II
me most TRADE secrets
place a 4" fan beside the gfx blowin IN to help cool the GPU used cable tie
voila