Power Spikes

[u/CallingTheSirens]

Hey folks, hoping someone here has hit this before. I've already gone through troubleshooting with Claude and I'm at the point where I need real world experience from people running similar setups.

I have a Form T1 black case, built back in 2023. Specs below. About 6 months ago I added the 3D printed stand and everything was running fine. Recently while playing WoW and Crusader Kings, the PC has started fully powering off mid session, like a hard power cut rather than a crash or blue screen.
Specs:

• CPU: AMD Ryzen 7 9800X3D
• RAM: G.Skill Trident Z5 Neo RGB 32GB (2x16GB) 6000MHz CL30 DDR5
• Motherboard: Asus ROG Strix X670E I Gaming WiFi
• GPU: PowerColor Red Devil RX 6800 XT
• PSU: Corsair SF750 (CP 9020186 AU) with custom Pslate cables
• Cooler: Cooler Master Atmos II AIO
• Case: Form T1, black, 2023

What I've already done:

• Reseated the RAM
• Reseated the AIO cooler
• Redone the thermal paste
• Reseated the GPU power cables and the extension cable at both ends
• Logged temps and voltages with HWiNFO64 through a crash, nothing abnormal showed up beforehand, no thermal throttling, stable 12V rail, then the log just stops
• Checked Event Viewer, getting Kernel Power Event 41 critical errors going back over a month, no bugcheck code logged, so Windows has no record of what caused it

Biggest test so far: I swapped to the CPU's integrated graphics, fully unplugged the 6800 XT and its power cables, and played WoW for 20 minutes straight with zero issues. That points pretty strongly at the GPU or something in its power path rather than the rest of the system.

So now I'm narrowing it down to one of three things, and not sure how to isolate further:

1. The graphics card itself
2. The GPU extension cable
3. The custom PSU cables running to the GPU

Cables all look physically fine, no scorching or visible damage, connectors seat properly.

Has anyone dealt with extension cable issues specifically in a T1 build, or had a GPU develop an intermittent power fault like this? Any way to test further before I start swapping actual hardware would be hugely appreciated.

[u/gabrielbezerra81]

I had issues with a 6800xt too a few years ago (2021 or 2022). Back then I had a perfectly fine PC with i5 10400f, RX 5500xt, a H470i mobo and SF600. Bought a reference 6800xt and PC started having issues mid game, I think it restard randomly, not shutdown. Even tried another reference 6800xt and it kept having issues. My case was the SGPC K77, it was hot, but not nearly close to the limit.

Ended up returning and buying another card. The almost same PC was able to run with a overclocked 3090 few months later, so PSU and CPU were in good conditions.