As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ISFD WILL NOT TURN ON. PERFORMED TROUBLESHOOTING IAW FIM 34-24-00-2, TASK 804, & WDM 34-24-15. FOUND NO OUTPUT VOLTAGE ON D4331J B12. REMOVED ISFD DEDICATED BATTERY CHARGER IAW AMM 34-24-03-000-801 AND AMM 20-10-07-000-801. INSTALLED SERVICEABLE ISFD DEDICATED BATTERY CHARGER. TESTED GOOD IAW AMM 34-2 4-03-400-801.