EXPO causing cold boot failure (VGA LED stuck on POST)

Posted by Harash93@reddit | buildapc | View on Reddit | 13 comments

My build:

For the first \~4 months everything was stable. Then one day after waking the PC from sleep, my monitors showed “No signal” and the keyboard had no response. After rebooting, the system powers on normally (fans, lights, etc.), but there is no display output and the white VGA Q-LED stays lit during POST.

The only way to recover is to fully cut power using the PSU switch for a few seconds. After that, it boots normally again—until the next cold boot, where the issue returns.

I’ve tried updating the BIOS, clearing CMOS, and testing both EXPO I and EXPO II profiles. I also tested lowering the RAM frequency to 5600MHz. After a CMOS reset, enabling EXPO allows the system to complete memory training and boot into Windows normally, and everything is stable once inside Windows. However, after shutting down and performing a cold boot, the system again fails at POST with the VGA LED and no display output.

I also tested with Memory Context Restore disabled. In that case, the first memory training after CMOS reset succeeds and the system boots into Windows, but subsequent cold boots still fail.

With EXPO disabled entirely, the system boots reliably every time without issues. The problem only occurs when EXPO is enabled.

I’m not sure what the problem is, especially since it was stable for several months before suddenly appearing. Any suggestions would be appreciated.