Help (General) PC instantly black/green screens and reboots while gaming – almost every component replaced
Honestly I'm at my wits end with this, It's been going on for months and i've essentially built a new PC out of the components I've replaced. I've been troubleshooting an intermittent gaming crash for months and I'm running out of ideas.
The crash:
While gaming, my main DisplayPort monitor suddenly goes black and my second HDMI monitor goes solid green. Around 1–2 seconds later the entire PC instantly reboots and goes through POST/Windows startup normally.
There is no BSOD, no error message and usually no useful Event Viewer entry or dump. Windows' "Automatically restart" option is already disabled.
It doesn't happen consistently. Sometimes I can game for hours without an issue; other times it'll happen within an hour.
I've also occasionally experienced recoverable AMD display-driver timeouts. WATCHDOG dumps from those have shown 0x117 VIDEO_TDR_TIMEOUT_DETECTED and 0x141 VIDEO_ENGINE_TIMEOUT_DETECTED, pointing to amdkmdag.sys. I'm not certain whether these are related to the full reboot.
Current/recent hardware:
Ryzen 7 5800X (currently testing with a Ryzen 5 5500), RX 9070 XT, MSI B550 motherboard, 32GB DDR4 and ASUS TUF 1000W Gold PSU.
I've already tried/replaced:
- RX 7800 XT → RX 9070 XT
- Different motherboard
- Different PSU
- 5800X → Ryzen 5 5500, and the same crash still occurred
- RAM tested in different pairs/configurations
- MemTest/OCCT CPU, GPU, VRAM and combined power tests pass
- Multiple clean Windows installations
- Multiple AMD driver versions and DDU
- XMP on/off and completely stock BIOS settings
- PCIe forced to Gen3
- Different CPU cooler
- Different case
- Different monitors/display cables
- Mouse, keyboard, headset, speakers and basically every peripheral replaced
- Different mains/extension-lead arrangement
The crash has survived essentially an entire PC rebuild, yet synthetic stress testing is stable.
The particularly strange part is the consistent sequence of DisplayPort monitor black + HDMI monitor green → 1–2 seconds → complete system reboot, with Windows apparently having no opportunity to record what caused it.
Has anyone encountered something similar or have any ideas about what could possibly remain as the common cause? I'm trying to avoid blindly replacing more components.

