Laptop xps1710 overheating - grafic card?

hi,

i bought the xps m1710 some years ago now... and in the last couple of months i had some problems like this

when switching it on it would appear with aaa aaa aaa all over the screen at the start when it is supposed to be just pitchblack and then when going further the screen appears black and with lines - as if it squached the whole screen several times and brings it out like zebra crossings

i reformatted the pc ... and somehow after logging into facebook - it started with this story again... so i thought it would be a virus - but when scanning kaspersky didn't find anything dodgy...

then i uninstalled it and via suggestion of a friend i installed avast! ... nothing dodgy found... i deleted some unidentified folder ... and it was fine for a few weeks... when it started it again...

after having noticed that the laptop heats up very quickly... i am thinking that maybe the grafic card has melted in all this time of running 'whole scans'... and indeed the ventilators are full of dust... i read about the aircompressor - which i will try out... but is it possible that this aaa aa aaa on the screen appears because the grafic card is f**d???