As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER 6.5 HRS OF FLIGHT R EGT WENT BLANK IN DESCENT AT 16000. CARRIED OUT INSPECTION OF ALL FOUR THERMOCOUPLES & ASSOCIATED HARNESS. NO FAULTS NOTED & ALL CONNECTIONS SECURE. REPLACED THERMOCOUPLE GASKET AT 8 O'CLOCK POSITION. CARRIED OUT ENGINE RUN & ALL INDICATIONS NORMALLY.