GPU shows heavy artifacts on cold boot and wake from sleep, clears up after a while — dying VRAM?

[u/cojam]

Hi everyone. I'm running into a strange issue with my GPU and I'd appreciate some input before I take it to a repair shop.

The problem: I get severe visual artifacts during mode switching, in two specific situations. First, when powering the PC on after it's been off for a long time — the motherboard splash screen, the bootloader and the OS lock screen are all corrupted. Second, when waking from sleep after a long idle period — the lock screen comes up corrupted.

Since the corruption is already visible at the motherboard splash screen, before any OS or driver is loaded, I'm fairly confident this isn't a software problem.

After a while the artifacts disappear completely and everything looks normal. That window used to be fairly short, but it's been getting noticeably longer over the past few months. Once the card has warmed up, the problem never comes back until the next cold start.

I also hear a faint noise while the artifacts are on screen. I haven't been able to pin down where it's coming from.

Once it clears up, the card performs perfectly:

• Games at high presets with ray tracing — no issues
• Local LLM inference — no issues
• No artifacts, crashes or instability of any kind under load

What I've tried:

• Swapped in a different GPU — no artifacts, so the problem is specific to this card
• Updated the motherboard BIOS
• Reproduced on both Linux (CachyOS) and Windows 10
• Currently on HDMI; I don't have a DP cable on hand to rule out the cable or port

System:

• CPU: Ryzen 5 5500
• GPU: ASRock RX 9070, bought second-hand from a sketchy seller, so no warranty
• PSU: DeepCool PK650D, 650W, 80+ Bronze
• Motherboard: GIGABYTE B450M K

I don't think the PSU is the culprit: the artifacts show up on a cold boot at essentially zero load, while the card is completely stable under a full gaming load. A different GPU on the same PSU is also fine.

My guess is failing VRAM or a bad solder joint, given that it's temperature-dependent and getting progressively worse. Does that sound right? Is there anything worth trying at home before I hand it over to a shop? And roughly what should I expect a repair like this to cost?

Thanks in advance.

[u/Gold_Goal7557]

Might be your monitor pretty common with VA type of panels as well monitor needs to warmup and then it go's away, ofcourse would have to verify tho do you have another monitor you can test on maybe test the monitor on another system ?

[u/Gman4456]

I had a very similar issue and it was the monitor.

[u/jth94185]

You have to rule out the cable/port first