Build guide / G3 3 of 3

Mini PC AC Power Recovery: BIOS Setup and Test

A safe State After G3 setup and three-cycle verification method for automatic boot after an outage, with service-recovery timing and UPS limits.

What State After G3 means

G3 is the mechanical-off state after AC input is removed. Firmware may label the recovery option State After G3, Restore AC Power Loss, AC Power Recovery or After Power Failure.

On the tested EQi12, the choices were S0 State and S5 State. S0 tells the machine to boot when power returns; S5 leaves it off.

This setting controls what happens after electricity returns. It does not make an abrupt outage safe, save database writes, or guarantee that Windows and services recover correctly.

Before changing the setting

Photograph the current firmware page and record the BIOS version. Confirm that Windows and applications can survive an ordinary restart before introducing physical power removal.

A database writing to disk can be damaged by uncontrolled outages. Automatic boot is a recovery feature, not a substitute for a UPS, application-aware backups or graceful shutdown.

Configure the EQi12

Enter AMI Aptio Setup during boot. On our unit, State After G3 was under the Chipset/PCH-IO area. Select S0 State, save changes and exit.

After Windows starts, re-enter BIOS once and verify that S0 persisted. Then boot normally and confirm network, Docker and application health.

EQi12 BIOS evidence used for automatic power recovery
The complete source batch includes the State After G3 page. BIOS revisions may place the setting elsewhere.

Three-cycle physical test

For each cycle:

  1. Start from a healthy Windows and application state.
  2. Record the time and current application health.
  3. Remove AC input using a controlled switch or unplug at the meter.
  4. Wait long enough for standby power to disappear.
  5. Restore AC input.
  6. Confirm automatic power-on without pressing the button.
  7. Measure time to Windows, network and required services.
  8. Save logs before repeating.

The EQi12 passed all three cycles. Jellyfin returned in about 40.77 seconds on average.

Use a result table instead of relying on memory:

Cycle Powered on automatically Network ready Required service ready Errors retained
1 Pass/fail Seconds Seconds Event/log reference
2 Pass/fail Seconds Seconds Event/log reference
3 Pass/fail Seconds Seconds Event/log reference

The completion time should be measured to the service users need, not to the firmware logo or Windows desktop.

Compressed web copy from the original physical power-removal, restoration and startup evidence.

Verify service state, not only the desktop

A visible Windows desktop does not mean the server is ready. Check:

Our recovery timing used application readiness rather than the first boot logo.

UPS and data integrity

Use a UPS when the server stores irreplaceable data. Configure the UPS software to shut the host down before battery exhaustion. Then use State After G3 to return after utility power is stable.

Test application backups separately. Our PostgreSQL and Redis restore tests were successful only after using a binary-safe Redis path; a power-recovery pass cannot replace that restore evidence.

When not to use automatic boot

Leave the system in S5 after power return if equipment requires inspection, cooling may be unavailable, network storage must start first, or automatic restart would create a safety risk.

The correct firmware value depends on the service design. The verified result here is that S0 recovery worked 3/3 on the tested EQi12—not that every mini PC or power environment behaves identically.

Common failure patterns

What to record for another mini PC

Photograph the exact menu and BIOS revision because names vary by vendor. Record whether the option offers Power On, Power Off, Last State, S0, or S5; these labels are not interchangeable. Then run the same controlled physical cycles and publish the denominator.

Combine this setting with the Windows home-server recovery test and Realtek Wake-on-LAN guide so power recovery and remote wake are verified separately.