"Power on AC attach" not working for Intel 12th gen in standalone mode

It’s a 12th gen Intel framework that I’m trying to run as a standalone server. I have both standalone and “Power on AC Attach” enabled in the BIOS.

All the standalone server part works perfectly (I think I’m using the latest BIOS - an update was required to enable standalone mode - how can I check the version from the BIOS itself?) but if I disconnect the power and plug it back in again, the lights turn on, and then after a little while there’s a flashing pattern, but the device doesn’t seem to actually start up at all.

If I press the power button after connecting the power then it boots just fine, but as a server I’d really like it to recover automatically if the power goes out momentarily.

There’s nothing unusual internally, just a disk & memory that seem to be working fine, I don’t think I’ve tweaked any other BIOS settings notably, and the only external connections are power and a USB-C ethernet dongle, both attached directly to the motherboard’s USB-C port (i.e. no expansion cards at all).

I am also trying to figure this out on 12th and 13th gen systems. Commenting to bump the topic.

how can I check the version from the BIOS itself?

You can press F2 during boot and go into the setup menu. It’ll show your BIOS version there. Its should be 3.0X something. The latest version is 3.08
See here: Framework Laptop BIOS and Driver Releases (12th Gen Intel® Core™)

Have you got the coincell battery installed?

Have you got the coincell battery installed?

Yes

You can press F2 during boot and go into the setup menu. It’ll show your BIOS version

Right, it looks like I’m running 3.06 so I haven’t actually fully updated this. Maybe that’s the problem (this issue is listed as a known problem for 3.06 on the Intel 11th Gen, maybe it also applies to 12th Gen but just isn’t listed as such?).

However, when trying to do the 3.08 EFI update, it doesn’t seem to actually work. More details here: 12th Gen Intel Core BIOS 3.08 Release - #685 by Tim_Perry. Any suggestions? I’m hopeful that this is the cause of the non-functional boot-on-attach behaviour, but I can’t actually update to test that.

You have to use the left side ports for the “Power on AC Attach” function to work correctly.

I was indeed using the right side ports, but I’ve just tested and no, power on AC attach doesn’t work on the left either.

Power on AC attach has had a few bug iterations and might be tracked in the Github BIOS bug tracker (don’t have the link handy as I am typing this). If not, consider entering a bug with your system setup so they can investigate it. Odds are you are not the only one with this issue!