Looks like dying video RAM to me, I guess it could be dry solder joints on the BGA chips that after warming up make enough contact to make the artifacts go away.

I've got a Quadro FX 3000 that exhibits similar behaviour.

If you press on the RAM chips one by one when the artifacts show up, do they change/get better/disappear?

It is like that, but any small movement of the pcb has an effect on artifacts. Will try tomorrow pressing one by one without moving the pcb.

There are times when no artifacts show even on cold boot, but they appear later, if the pcb isnt forced up a bit.

Strange problem 😀

It definitely sounds like there's a bad solder joint. When you flex the pcb you temporarily fixing the connection. Most likely it's one of the solder balls under a ram chip or the GPU is cracked or damaged

Ill make a recording today how it behaves when Im gently toching her hotspots.

Tried a bit in the morning, and nothing happened pressing the ram chips or cpu, but bending the pcb worked like a charm.
Agree that its definitely probably a bad solder joint, now the question is just where 😀.

Last video record... Pressed all ram chips one by one and core. Nothing really responds, but bending pcb always works.

https://www.youtube.com/watch?v=V93Mnl_82Cg

Im waiting for my liquid flux to arrive, for another project, just dont want to heat everything up, fucking up even that, what isnt broken right now 🙁

Dolenc wrote on 2021-06-14, 17:36:

Last video record... Pressed all ram chips one by one and core. Nothing really responds, but bending pcb always works.

https://www.youtube.com/watch?v=V93Mnl_82Cg

Im waiting for my liquid flux to arrive, for another project, just dont want to heat everything up, fucking up even that, what isnt broken right now 🙁

Is there a particular part of the PCB that responds to flexing? It's still likely to be a dry solder joint somewhere in the vicinity of the flex!

Pressing up near the pcie power inlet works best, but pressing up mostly everywhere works.

Pressing down makes things worse.

Not a bad idea, I will try to zone presses a bit more precise and see if theres a sweetspot.

Does the power connector seem loose at all?

No.. Stuck well in there

Dolenc wrote on 2021-06-14, 18:49:

No.. Stuck well in there

I think he was asking if the connector on the card itself felt loose, like it might be the owner of the bad solder joint?

Yes that's exactly what I meant.

No no, stuck on their solid.

Maybe, bake it again?
I know it is a bit dangerous, but all of the solder will melt and get solid again, maybe fixing a bad solder spot. It helped me with my ATI card back in the day when it was only 3 years of age. It had the exact same issues. The downside was that it reoccured again but worse after a month of six or so.

Oven baking is a largely pointless exercise. Lead-free solder will have a higher melting point than you think, so all you are really doing is thermally expanding and contracting the substrates and parts.

It "might" be worth getting someone to reflow the GPU and BGA RAM chips using a proper hot-air SMD rework station and some good flux, but there's definitely the possibility for it to get a lot worse.

AFAIK X850 is not lead-free card.

P.S.
I'm fairly certain that this card is not true X850XT, it has 128-bit memory bus.

Yea no oven, besides hard to check the temperature its also hard to soak everything in flux, that clears any oxidation on the joints. This is the main problem why it usually fails again after a while.

Im waiting for my flux to arrive, for another r9800 card that is mostly dead, then Ill see what Ill do with this one, prob try to reflow just the memory first and see what that does. It does still work now, even if I have to pre-heat it 😁

If I manage to fix anything Ill update the topic ofc.

Dont know about lead-free, should be, since they started with that in 9x00 generation, but 256bit it is, card runs fine, just the right spec for 1080p and around 2000 era games.

Just an update, that wont help anyone 😁

I tightened the cpu cooler screws, they were really loose, cus I didnt want any pcb bend. Now they are as snug as they go.

And imagine that, no more artifacts. Not when cold, not if I move the card, no ziptie needed....
Been like that for a few days now, so I guess its "fixed".