What was found
AFTER SHUTDOWN, RED BOX ON #2 ENGINE EGT GAUGE. GROUNDED - YES. PERFORMED AN INPUT MONITORING CHECK OF THE #2 ENGINE T49.5 PROBES PER B737-800 FIM 77-21 TASKS 803 AND 805. FOUND S3 BLANK, WITH AN ASSOCIATED FAULT 77-20862 ON LEGS 3 AND 4. PERFORMED A T49.5 PROBE AND EGT SYSTEM INSPECTION AND CLEANING PER B737-800 AMM 77-21-01-200-801-F00 AND 77-21-00-140-801. ALL RESISTANCE VALUES WITHIN LIMITS, BUT FOUND A LOOSE S3 PROBE CONNECTOR. COMPLETED EGT INSPECTIONS AND THE EEC TEST NOW PASSES. REPAIR CONFIMATION - ACCOMPLISHED POWER ASSURANCE CHECK PER AMM 71-00-00-700-813-F00, NO FAULTS NOTED AND PARAMETERS ALL WITHIN LIMITS.