I have a Sony Vaio VGN-FZ21Z, about 18 months old (warranty expired after 12). A few weeks ago my laptop screen went really dim, I could only see a shadow of the icons, when I start the computer up it the screen flickers and then goes dim. I connected an external monitor and continued to use it, now that has problems. The screen resolution the external computer won't change from 640x480 (when the laptop recognises it. At first I thought it was the laptop screen bulbs and I needed a new screen but now I'm concerned it's the graphics card, any ideas?
It is not the graphics card. It is the backlighting module. You can go into the bios set up and possibly change the resolution of the external display. If the graphics chip was bad you would get NO VIDEO at all. You may also want to check you manual to see if there are settings listed for the function keys that allow you to change the video resolution of your external display.