What was found
FLIGHT 7820, AIR TURN BACK DISCREPANCY, SHORTLY AFTER TAKEOFF, THE CREW RECEIVED A MASTER CAUTION INDICATION ON THE CREW ALERTING PANEL. THE NR 1 ENG ITT INDICATED 500, NR 2 ENG ITT INDICATED 850, WITH TORQUES SET AT 90%. THE REW ELECTED TO RETURN, NO EMER WAS DECLARED. AFTER EXTENSIVE TROUBLESHOOTING, MX FOUND THAT THE THERMO COUPLER BUS BAR HAD SHORTED. MX CLEANED THE BUS BAR. PERFORMED A BORESCOPE INSPECTION, PERFORMED ENG RUNS. NO DEFECTS NOTED. OPERATIONS CHECKED FLIGHT STILL TO BE DONE.