4850 dead? Help.

[Slmhofy]

So I've been running my 4850 for about a week now no problems, great actually, just hot and annoying fan. So today I added my old 939 DD TDX block to it with some fabrication and added it to my loop. After a couple minutes into windows, I got a green screen with vertical paterns and then a reboot. I tried reseating the vid card, worked for a bit and tried ATI autotune, got the same green screen but it didn't lock up the cpu, came back to desktop, then a couple seconds green screen and lock up.

Took card out, cleaned gpu and block, remounted and put back in computer, same thing. Took card back out and put stock hsf on and pretty much the same thing. Sometimes works for a few minutes and others just one or 2.

Any ideas?
Thanks.

[{PGA}AfterShock]

sounds like the vid mem overheated, did you use anything to cool the memory chips when you put the TDX block on?

[Slmhofy]

Hmmm. Interesting thought. No I didn't but they never felt hot at all. And I would go for that reasoning if not for the fact that the card still does the same thing with the stock cooler back in place ;(

[TimoneX]

I recently got an HD4850 from a fine fellow in the classies. NEway when I first tried it had creepy artifacts and crashes to desktop similar to what you're describing. A simple reflashing of the stock bios fixed 'er right up and I haven't had a problem since (about a week). I guess the gpu bios got scrambled during shipping. Call it a magnetic attack. :)

Possibly give a reflash a whirl.

[corruption]

Hmmm. Interesting thought. No I didn't but they never felt hot at all. And I would go for that reasoning if not for the fact that the card still does the same thing with the stock cooler back in place ;(

Unfortunately, there is a minor flaw in your logic. If something on the card overheated when you used the block, and was damaged, putting the stock cooler back on won't fix it. Think about it like this....if you crack your skull open, putting a helmet on after the fact won't fix your head. If the artifacting was a symptom of overheating, but not to a point that permanent damage was done, then putting the stock heatsink back on would fix the issue.

I know that on the 8800GT that I have, the power regulation circuitry needs to be cooled. If the 4850 is the same, and I suspect that it is, you could have damaged the power circuitry if it did not receive proper cooling.