What was found
WHILE ACCOMPLISHING T/C 7827300, FOUND NR 1 ENGINE FAULT 77-10841, THE TOP RT SIGNAL IS OUT OF RANGE FLIGHT LEGS 1, 2, 3, 4. ECONOMIC FAULT, ESN894613. ACFT GROUNDED. ACCOMPLISHED TROUBLESHOOTING IAW FIM 77-21-TASK 801. INITIAL CHECK OF INPUTS ON CDU SHOWS NO INITIAL FAULTS. ACCOMPLISHED T49.5 PROBE AND EGT SYS INSPECTION IAW AMM 77-21-01-200-801-F00. PROBES S1, S2, AND S3 RESISTANCE IS EXCESSIVELY HIGH. R & R S1, S2 AND S3 T49.5 PROBES IAW AMM 77-21-01. OPS CHECK NORMAL.