As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LIGHT ELECTRICAL SMELL IN BOTH COCKPIT AND CABIN FOR NO MORE THAN 20-30 SECS SMELL DISSIPATED SHORTLY AFTER. 1 ENGINE AND APU RUNNING, BOTH PACKS WERE ON WHILE ON GROUND WAITING FOR OUR GATE.-C/A-C/W EMB 175 FIM TASK 21-20-00-810-801. COULD NOT DUPLICATE. NO DEFECTS NOTED.