What was found
(CAN) ON GROUND, FLIGHT CREW REPORTED THAT NR 2 ENGINE FIRE DETECTION CIRCUIT BREAKER (CB) J7 ON THE RT ESSENTIAL CB PANEL, POPPED. AS THIS WAS A HARD FAULT, THE ACFT WAS REMOVED FROM SERVICE. DURING TROUBLESHOOTING, BURNED SHIELD SOLDER SLEEVES WERE FOUND AT ELECTRICAL CONNECTOR 9811-J604, LOCATED ON THE RT NACELLE FIREWALL. WIRES WERE RE-TERMINATED, ALL AFFECTED SYSTEMS TESTED AND THE ACFT RELEASED BACK IN SERVICE. ACFT TIMES: 5529:20, FLIGHT HOURS, 4410 CYCLES.