What was found
AT FL 370 RIGHT ENGINE WENT TO EEC ALTERNATE MODE WITH ASSOCIATED MASTER CAUTION AND ENG LIGHT. ABOUT 15 SEC LATER THE ENGINE RUMBLED AND VIBRATED AND RPM ROLLED BACK SELECTED THRUST LEVER TO IDLE AS RPM WAS DECAYING THRU 51% USED EEC ALTERNATE QRH CHECKLIST TO PUT BOTH ENGINES IN ALTERNATE AND LANDED. F/CS - 75-10432 73-20252 73-20012 73-20242 73-20272 73-20052 73-20342 79-21092 73-21452 78-21542 73-20262 78-21532 77-20862 73-20122 73-20182 75-20392 75-20442 75-20592 73-20812 75-20822 75-20832 73-20062 75-20292 75-20362 75-20542 77-20872 73-11722. <[01] INSPECTED WORK ABOVE; [02] PREFORMED PREPARATION GEAR BOX PAD REMOVAL AND INSTALL; BOROSCOPED BOOSTER & VAINS 72-00-00-200-805-F00. HP COMPRESSOR 72-00-00-200-803-817-F00; HPT BLADES 72-00-00-200-803-F00; LPT 1-372-00-00-200-808-F00; LPT-4 72-00-00-200-809-F00; GEAR BOX PAD REINSTALLED PER AMM 72-00-00. R&R?D #2 ENGINE EEC PER AMM 73-21-60; OPS CHECK GOOD. R&R?D ENGINE CONTROL MODULE (P5-68) PER AMM 73-21-12. OPS CHECK GOOD. NO OTHER DEFECTS NOTED.