As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TOWER REPORTED UNABLE TO PICKUP TRANSPONDER SIGNAL. COULD NOT DUPLICATE PROBLEM. INSPECTED UNIT AND FOUND FACEPLATE CRACKED AND PHOTOCELL NOT WORKING. REPLACED FACEPLATE P/N 200-02020-0001 AND PHOTOCELL V301 P/N 134-05005-0002. TESTED UNIT. ADJUSTED PULSE AND FREQUENCY TO SPECS. BENCH CHECK GOOD.