My Dell M90, FX2500m died on me last year about September exactly after 5 years when the warranty ended . Same symptoms, the screen went gibberish and then blank screen after a few restarts. Not wanting it to die on me, I decided to bake the card and it's been working well until today (fingers crossed). That's been 6 months now
I should replace it soon, it's been getting slower with new programmes being so resource hungry.