As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOS - CREW REPORTED FLAP LEVER SELECTED TO 1 DEGREE AND NOTHING HAPPENED. FOLLOWED QRH AND EXTENDED SLATS WITH ALTERNATE FLAP SWITCH. AIRCRAFT REMOVED FROM SERVICE. REPLACED FLAP LEVER POSITION TRANSMITTER AND FLAP SKEW SENSOR. SYSTEM GROUND CHECK NORMAL OPERATION.