As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 ENGINE PERFORMED TASK CARD 78273000 HAD FAULT CODE 77 20872 LONG TIME FAULT, THE TOP LEFT EGT SIGNAL (T495S4) IS OUT OF RANGE. VERIFIED EGT PROBE S4 AND HARNESS CJ10 TO BE BAD REPLACED IAW MM 77 21 00, ALL GROUND VERIFICATION TESTS PASS.