As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STRONG ACID ODOR IN COCKPIT JUST PRIOR TO TAKEOFF WHEN TRANSPONDER WAS TURNED ON. RETURNED TO GATE. FOUND WEATHER RADAR INDICATOR INTERMITTENT PER CREW. REMOVED AND REPLACED WEATHER RADAR INDICATOR AND TRANSCEIVER CK OK. INSPECTED FWD AND MAIN E AND E COMPARTMENTS AND NO ODORS FOUND. INSPECTED WIRING TO WEATHER RADAR INDICATOR, NO PROBLEMS FOUND.