As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT THE NR 1 ITT INDICATOR WENT TO ZERO. THE AIRCRAFT RETURNED TO HOME BASE WHERE AN UNEVENTFUL LANDING WAS MADE, DURING RETURN FLIGHT THE INDICATOR BEGAN TO WORK BUT WAS LOWER THAN NORMAL AND ERRATIC. THE GAUGE WAS PARTIALLY REMOVED FROM THE PANEL AND THE PROBLEM COULD BE DUPLICATED BY TAPPING ON THE BACK OF THE GAUGE. THE GAUGE WAS REPLACED WITH AN OVERHAULED UNIT AND GROUND OPERATIONS CHECKS WERE NORMAL. THE AIRCRAFT WAS RETURNED TO SERVICE.