What was found
ON FLIGHT 4468 DURING CRUISE THE CREW REPORTED AN ENGINE 1 THRUST REVERSER FAIL. ITEM DEFERED PER MEL 78-1. AUTH 070981M-C. COMPLIED WITH PROCEDURES AS PER MEL. TRANSFERD TO MIC SHEET. AIRCRAFT REMOVED FROM SERVICE. PERFORMED OPS CHECK OF E1 TR IAW AMM 78-32-01. OPS CHECK GOOD. NO FAULT NOTED MEL 78-1 RESTORED. REPEATED AND RE-OPENED. MAINTENANCE PERFORMED FIM TROUBLESHOOTING TASK 78-30-00-810-801-A. COULD NOT DUPLICATE. TROUBLESHOOT UP TO STEP 2, SUBTASK 817-013-A, PAGE 205. FURTHER TROUBLESHOOTING REQUIRED. MEL 78-1 REMAINS OPEN. MAINTENANCE COMPLIED WITH WORKSCOPE. COULD NOT FIX PROBLEM MEL REMAINS OPEN. AIRCRAFT RETURNED TO SERVICE. THE CORRECTIVE ACTION INFORMATION IS STILL PENDING.