As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EPSU EXT LOAD EMER L R&R 11WL EMERGENCY POWER SUPPLY UNIT PER AMM 33-51-38-400-001-A, DID NOT HELP. INSTALLED BACK THE OLD EPSU AND BATTERY. FOUND ON EPSU EXTERIOR LIGHTS FAULT LIGHT ON SEE PIC. CHECKED OVERWING LIGHTS FOUND AFT LIGHT NOT WORKING P/N GE1810. RELAMPED LH THE EMERGENCY OVERWING LIGHT PER AMM 33-51-15-400-001-A. OPS CHECK GOOD. EPSU TEST PASSED.