What was found
THE CREW REPORTED THAT DURING CRUISE FLIGHT, NR 2 ENGINE (N1) SMOOTHLY ROLLED BACK ABOUT 25-30 PERCENT AND THEN SMOOTHLY CAME BACK UP, IT DID THIS 3 TIMES IN ABOUT 15 MINUTES AND THEN RETURNED TO NORMAL. ON LANDING, GOT E1 EXCEEDANCE ON EICAS. THE ACFT WAS REMOVED FROM SERVICE. DOWNLOADED CMC, FOUND 2B INPUT FAIL MESSAGES. R & R THE 2B FADEC IAW AMM 73-25-10. GROUND RAN CHECK AND IT WAS GOOD. NO DISP E1, E2 NOTED. THE ACFT WAS RETURNED TO SERVICE.