4870, Ghost in the machine?!

This little problem is involved with the 3 red LED's staying on, on my 4870. This started happened about 3 weeks ago, (the computer is only 4 months old). Essentially, my computer will run fine for x amount of time, then close itself down as though its been unplugged.

Then, when booted up again the 3 red leds will have turned on solid. (All bar the one signalling complete GPU failure.) Usually, I can resolve this by unplugging the graphics card, and replugging it a couple of times, then turning the pc on again.

This led me to think that perhaps there is a power issue/connection problem. As far as I can tell everything is connected properly, reinforced by the fact that the shut downs are seemingly random, sometimes after 2 hours, other times after 10!


It is a Powercolor 4870 512mb model.

Any help is much appreciated.