As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ELECTRICAL FUMES NOTICED AND SMELL INCREASED. PERFORMED QRH PROCEDURE. AS A PRECAUTION, PULLED ATC NR 1 C/B ALSO AND SMELL DISSIPATED. FOUND NR 1 TRANSPONDER HOT TO THE TOUCH. REMOVED AND REPLACED NR1 TRANSPONDER IAW MM 34-53. SELF TEST GOOD. THIS CLEARS MDR 147159, PLACARD REMOVED.