
Gigabyte B550M DS3H AC R2 - fails to boot on AC power loss
Help me PCMR - this issue has me screwed. I've never seen anything like it before - and don't know what to do.
Troubleshooting steps: https://www.youtube.com/watch?v=CNWWvC_6zD8
The PC won't boot after AC power has been lost unless I reset the BIOS, then allow it to start from scratch again.
After configuring the BIOS (even just XMP + SVM), the PC will always boot fine until AC power is lost again. Then either the BIOS will reset or the PC will just fail to boot again.
- CPU: Ryzen 5700G.
- RAM: 4 x 32Gb CMK64GX4M2E3200C16 Vengeance LPX 64GB 3200MHz DDR4
An unconfigured Windows 11 install is on the NVMe SSD just for testing purposes.
CMOS battery measures at 3.1v - which seems to remove that avenue as a fault.
I have tried 1 DDR stick, 2, and 4 with no difference in behaviour.
Powering off via the switch on the Corsair power supply when Windows is booted will cause the same failure to boot problem - requiring a BIOS reset via the jumper to bring it back to life.
The board has been RMA'ed to Gigabyte - who sent it back saying No Fault Found.
Have tried BIOS versions F3 and F4a - Gigabyte sent it back to me with F3.
Help me PCMR - you're my only hope. What the hell am I missing?