Processors

[cheerful]

Ryzen 7 5700G

MSI MPG B550 Gaming Plus, with the latest firmware and driver

32 GB RAM

Windows 11 Pro with everything updated.

Monitor 1: DP, Acer QHD.  This is connected all the time

Monitor 2: HDMI, TV, FHD.  This is not connected in most of time.

With the PC on and Acer as the main display, I connected the TV as an extended display.  Everything worked fine.  Then I turned off the TV with HDMI still connected.  The PC was idling and went into hibernation.  I was able to wake it up with USB mouse and it all worked fine.

Next morning, I was still able to wake up the PC using USB mouse.  However, by the afternoon, it failed to start.  There are 2 long beeps, indicating POST failed.  The Acer monitors showed all white for a few seconds and then went black.  Disconnecting TV did not help.  Turn PC on/off did not help.  Then I unplugged the power, waited for 10 seconds, re-plugged it, pressed the power button, it booted up normally.

This has happened twice in the last few weeks.  The first time I was not sure.  Now I'm pretty sure this is the same problem and it's related to using 2 monitors at the same time.  It never happened without the TV plugged.

What can I do to fix it?

Thanks

[misterj]

cheerful, I assume both monitors are connected to the MB (no graphics card). The AMD specifications for your processor does not say how many monitors the 5700G supports. I suggest you open a support request. Enjoy, John.

[cheerful]

OK, I will.

Just to be clear, I can connect the 2nd monitor and it works fine.  The issue is that it won't boot successfully next time

[misterj]

cheerful, for sure, open a service request with AMD and your MB vendor. Thanks and enjoy, John.

PS: Sounds like a MB problem to me.