DIAGNOSIS The control board is locked up or has lost power. This is often a faulty power connection or a corrupted memory state.
FIX Unplug the power cord from the wall outlet and from the back of the air fryer unit. Wait 2 full minutes. Firmly reconnect the cord to the appliance first, then plug it into the wall. The display should show the time.
IF THAT DIDN'T WORK The 12V DC power supply inside the unit, which feeds the control board, has failed. You'll need to open the base to test and replace it.
HEADS UP Always disconnect power at both ends for a hard reset. Just unplugging from the wall sometimes isn't enough for this model.