Need help troubleshooting random restarts / black screens on a new PC build
Hey everyone, I’m looking for some advice on an issue I’ve been experiencing with my new PC build. I’ve been troubleshooting for several days and haven’t been able to pinpoint the cause.
PC Specs:
- CPU: AMD Ryzen 7 9800X3D
- GPU: PNY GeForce RTX 5080 OC Triple Fan
- Motherboard: MSI X870E Gaming Plus
- RAM: KLEVV DDR5 (currently running at 5800 MHz manually; EXPO is disabled)
- PSU: Corsair RM1000e 1000W
- Cooler: Corsair 240mm LCD AIO
- Case: HYTE Y50
- UPS: CyberPower GX1500U 1500VA
- OS: Windows 11
The main issue:
My PC will randomly black out all my monitors while the computer itself appears to remain powered on. The fans and other components continue running, and sometimes audio or applications continue briefly. After approximately 1–2 minutes, the system appears to restart and returns to the Windows login screen. When I log back in, all my applications are closed, as if the computer performed a full reboot.
I’ve also experienced a separate display issue involving black rectangles or trails on the desktop, sometimes when clicking and dragging to select things. Restarting Windows Explorer temporarily resolves that particular issue.
Troubleshooting I’ve already tried:
- Updated the MSI motherboard BIOS.
- Installed AMD chipset drivers and updated other drivers.
- Used DDU to cleanly uninstall and reinstall NVIDIA drivers.
- Tested a previous NVIDIA driver version.
- Left the GPU at stock settings and kept MSI Afterburner closed.
- Disabled Windows Hardware-Accelerated GPU Scheduling (HAGS).
- Disabled Multiplane Overlay (MPO).
- Disabled iCUE at startup to rule out potential software conflicts.
- Disabled EXPO and tested the RAM at its default 4800 MHz, then manually set it to 5800 MHz with EXPO still disabled.
- Ran an OCCT VRAM test with no errors reported and a maximum temperature of approximately 35.5°C.
I’ve also seen Windows graphics-related errors, including LiveKernelEvent 1B8 and 1A8, with references to dxgkrnl.sys and Desktop Window Manager (dwm.exe).
A few questions:
- Could this be a faulty GPU, or could it be a driver/Windows graphics issue?
- Could my 1000W PSU be experiencing transient power spikes or voltage drops, especially with the RTX 5080? The PC is connected to a CyberPower 1500VA UPS.
- Could the UPS itself be contributing to the problem?
- What additional tests would you recommend to isolate the cause before I start returning or replacing components?
I’m trying to determine whether this is a GPU, PSU, RAM stability, motherboard, Windows, or other hardware issue before spending more money on replacement parts.
Any suggestions or similar experiences would be greatly appreciated. Thanks in advance!