Flickering lines up and down screen with HD 4890

what are your gpu temps under load ?and that psu don't look good to me!

The temps are about 44 at idle and under load about 70ish. I just tested it with my spare PSU, it's a Vantec ion2 520watt. Just a few days ago the card was working fine and now it isn't.

Oh, I forgot to mention that I still get flickering lines across the screen with the Vantec PSU.

have you tested your card in some other pc or, have you tested some other card in your pc?

Yes, and if it is possible check that your GPU fan is running properly and that theres no evidence of overheating or blown capacitors. Then report back to us

I have not tested the card in another PC but I will do this weekend. The fan is definitely working fine and the card is not overheating. It is about 75* during Furmark stress test.

If the card does not work in another PC, what should I do with it. RMA it? bake it XD or sell it?

It is going to be difficult to RMA because I bought it off Amazon and my cousin brought it into South Africa for me. The costs would be much too high for all the shipping costs etc.