As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL370 2.5 HOURS INTO FLT, NOTED ELECTRICAL ARCING SOUND FROM CAPTAIN'S FWD WINDSCREEN, TURNED OFF "FWD WINDOW HEAT" ON CAPTAIN'S SIDE AND ARCING SOUND STOPPED. CAME BACK ON INTERMITTENTLY WHEN SWITCHED ON. ACFT GROUNDED. REMOVED AND REPLACED THE NR 1 WINDOW IAW AMM 56-11-11-000-801 AND AMM 56-11-11-400-821 STEPS 3A THRU 3G. COMPLETED INSTALLATION OF THE NR 1 WINDOW IAW AMM 56-11-11-400-821 STEPS 3H THRU 3I. OPS TEST GOOD.