What was found
WHILE ENROUTE, AIRCRAFT HAD A VARNR LIGHT ILLUMINATE AND EXPERIENCED AN APPROXIMATE 30% ENGINE SPLIT WITH NR 2 ENGINE GOING LOW. AIRCRAFT VARTOM’S SYSTEM WENT INTO MANUAL MODE. PILOT ATTEMPTED TO BEEP UP THE NR 2 ENGINE WITH COLLECTIVE TRIM SWITCH WITH NEGATIVE RESULTS. COLLECTIVE TRIM SWITCH WOULD ONLY INCREASE THE NR 1 ENGINE, WHICH WAS ONLY DONE MOMENTARILY TO CHECK IF SWITCH WAS WORKING. THE NR 2 ENGINE WOULD NOT RESPOND TO COLLECTIVE TRIM SWITCH. ELECTED TO DO A RUN ON LANDING AS A PRECAUTION IN ORDER TO NOT EXCEED ANY LIMITATIONS ON THE NR 1 ENGINE. NO DAMAGE TO AIRCRAFT AND NO LIMITATIONS EXCEEDED.