As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN FLIGHT NOTICED ELECTRICAL ARCING (BRIEFLY) AT TOP LT HALF OF CAPT SIDE WINDOW. ARCING STOPPED IN 2-3 SEC IMMEDIATELY FOLLOWED BY "L WINDOW HEAT " CAUTION. QRH WAS FOLLOWED EXCEPT L WINDOW WAS NOT RESET ON. R & R LET SIDE WINDOW IAW AMM, REF TO IPC 56-12-01, ITEM 5B, OPS CHECK OF THE HEATER GOOD.