As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#2260, MAD-BOS. (ETOPS) ATC/XPDR 2 FAILED DURING PRE FLIGHT ( ATC SYSTEM - TRANSPONDER SINGLE POSITION ); OPERATIONAL TEST OF THE ATC WAS ACCOMPLISHED AS PER AMM 34-52-00-740-004-A.NO FAULTS NOTED ON BOTH CHANNELS MX-4 UPDATED. PLACARD REMOVED.