As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOSS OF SAARU-SECONDARY ATTITUDE AIR DATA. SHORTLY AFTER T/O CAP PHONED PILOT TO DISCUSS LOSS OF SAARU-SECONDARY ATTITUDE AIR DATA REF UNIT (MEL-3421J). AFTER MUCH DISCUSSION IT WAS DETERMINED BEST TO RETURN TO SFO FOR REPAIR. TROUBLESHOOTING IDENTIFIED SECONDARY ATTITUDE AIR DATA REF UNIT AS FAILED. REPLACED SAARU. SYSTEMS OP CHECKED OK FOR SERVICE.