Radeon HD 5770 failing.

[B1zmark]

Hello! I am 99% sure my GFX card needs replaced but cash is an issue at the moment so I'm trying anything to get this working again. Any input is helpful

Hardware:
CPU: Phenom II x4 840
RAM: 8GB (2x4GB) Ripjaws 1333
MOB: Biostar A780L3L 760G
PSU: Evo Labs 650W
GFX: XFX Radeon HD 5770 1024MB - Dual DVI output

The issue is my PC crashing, here is exactly what happens when it crashes (everytime, with no variation).

1. Display goes on to stand-by.
2. Sound starts to repeat
3. Sound stops.
4. PC fans go to 100% speed and stay there.
5. PC remains like this until reset switch is pressed.

This happens whenever I try to play a game. This is not a new build, its been working fine for 2 months then this crash happened randomly a few times over the past few days - but worked fine on reboot, then yesterday it simply done it on every 3D application.

Steps taken to remedy.

-Reinstalled drivers from scratch using a driver cleaner software (both XFX and AMD driver sets).
-Checked power usage, estimated around 484W usage, meaning plenty to spare.
-Reseated GFX card.
-Tried different DVI output.
-Checked card temperature and upped fan speed to max. Crashes happening with card only at 40oC

Some 3D applications will run for a very short time before crashing. Older 3D applications (read: Half Life 1 engine) ran for about 10 minutes with no crash.

If anyone has any idea, please let me know.

Thanks.

 

[B1zmark]

I have yet to try underclocking, could this potentially change things? Although my stuff isnt overclocked.

 

[dannoddd]

Even though you may have enough power, it could be a fault in the power supply.
Try swapping out components if you have them on standby.
Disable any and all overclocking if you have it enabled.
Otherwise it's probably the GPU or PSU that's the problem.

 

[B1zmark]

I have an older but tried and tested 650W. ill try swapping it out.