Asus Chromebox 4 (Duffy) powers on automatically after AC loss despite BIOS setting

Bug Reports Firmware Bugs
1

System Details

  • Device: DUFFY
  • OS: Windows
  • Firmware Type: UEFI Full ROM
  • Firmware Version: coreboot MrChromebox-2603.2, 5/17/2026
  • Internal storage type: NVMe

Summary of the Issue

The UEFI firmware fails to respect the “Power off after AC loss” configuration setting in the BIOS menu. When this option is configured to keep the system powered off, the device still immediately boots up as soon as AC power is restored.

Steps to Reproduce

  1. Boot into the MrChromebox UEFI settings menu.

  2. Navigate to the Platform tools and set the AC Power Loss state to Power off then Save changes and exit.

  3. Allow the operating system to boot, then perform a clean, normal shutdown.

  4. Unplug the AC power cord from the back of the Chromebox.

  5. Wait 10 seconds, then plug the AC power cord back in.

Expected Behavior

The Chromebox should remain completely powered off when AC power is re-applied, requiring a physical press of the power button to boot.

Additional Notes

I don’t know if this also because of my Cmos battery gone and i can’t add another new cmos battery because the cmos holder is broken

2

not having a CMOS battery doesn’t help

3

I guess it’s the firmware, then. I think the issue also occurs on 10th-gen Chromeboxes. like the slow booting

4

slow boot is fixed. I’ll check the auto on function before next release

1 Like
5

Yes, that’s correct! I was so happy when you fixed it. I always check the latest updates on MrChromebox for any bug fixes related to Comet Lake processors.

6

It IS the problem of CMOS battery, at least on the Asus Chromebox 3.