Is the power cable connected to the ScanSnap and the AC outlet?
Connect the power cable to the ScanSnap and the AC outlet.
Is the ADF paper chute (cover) open?
If the ADF paper chute (cover) is closed, open the ADF paper chute (cover) to turn on the ScanSnap.
Are you using the AC adapter and cables that are bundled with the ScanSnap?
Use only the AC adapter and cables that are bundled with the ScanSnap.
Is the AC adapter and the AC cable connected properly?
Insert the AC cable plug all the way into the AC adapter.
Has the computer just been started up, or resumed from sleep mode?
When the ADF paper chute (cover) is open while the ScanSnap and the computer are connected via a USB cable, the ScanSnap is turned on/off in conjunction with the computer's power.
When the startup of the computer is not completed or the computer is in sleep mode, the ScanSnap may be turned off.
Wait until the [Scan] button on the ScanSnap lights on.
An error may have occurred in the ScanSnap
Disconnect all the cables from the ScanSnap, reconnect them after 10 minutes, and then check if the problem is solved.