As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING A ROUTINE OVERNIGHT CHECK OF THE CABIN LIGHTS THE FRONT 4 PSUS ON THE LT SIDE WOULD NOT TEST. FURTHER INVESTIGATION REVEALED THAT CONNECTOR 3320J35/P40 WAS SHOWING SIGNS OF OVERHEATING/BURNING ABOVE THE FIRST PSU FILLER PANEL ON THE LT SIDE.CONNECTOR 3320J35/P40 REPLACED AND FUNCTION CHECKED SERVICEABLE.