As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TROUBLESHOOTING OF M277846 LANDING LIGHT INOP, MTC FOUND OVERHEAD LANDING LIGHT PANEL BURNED INTERNALLY AND WIRING SHORTED. OVERHEAD LIGHTING PANEL REMOVED & PLACED IN 5X STORES. REPLACED SWITCH 31-58, 51-59 & 51-61 AND ACCOMPANING WIRES TO DISCONNECTED PER SWPM. CHECKED REMAINING WIRES, ALL OKAY.