B737-700
Maintenance Airframe; Maintenance Powerplant
Communication Breakdown; Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; MEL; Human Factors
Went down line for a thrust reverser fault on Number 1 engine.  Upon arrival; contacted Maintenance control for information. Was informed that contract maintenance found the Inboard Thrust Reverser sleeve not stowed.  Examined the logbook for more information.  Original LP (Log Page) Stated 'Number 1 Eng. reverser light on.'  Subsequent log page by contract maintenance 'TRIED UNSUCCESSFULLY TO LOCKOUT NUMBER 1 TR (Thrust Reverser). BLOCKER DOORS PARTIALLY DEPLOYED.' Went to pull up MEL (Minimum Equipment List) for 'Reverser Light.' Read procedure which said to deactivate thrust reverser; downgrade CAT (Category) III; and Placard.  Printed out deactivation procedures in operations office and went out to the aircraft and followed every step.  Called Maintenance Control and verified all lockout procedures were followed and filled out log page according to Maintenance Control instructions. Maintenance Control told me to write down MEL.  I failed to realize that Maintenance Control gave me a different MEL number than we thought we were accomplishing.  I was never asked to check the opposite engine for operation and it is not required for MEL X; which we believed we should be performing.I believe contract maintenance pulled the Engine Number 2 Circuit breakers for it's Thrust reverser in error and did not document it.  I missed performing an operational check on the Number 2 engine because I was following procedures for MEL X which has you lock out the effected engine; but NOT check the opposite engine for Trust reverser operation.  I did not realize that the Maintenance Controller had me performing a different MEL; which DOES require checking the opposing engine for operation after locking out the effected engine.  I believe the pilot missed the Number 2 Engine circuit breakers out but not collared; and the subsequent landing the thrust reversers did not deploy on Number 2 the engine.I believed we performed all procedures correctly; but performed an incorrect MEL by accident.                                      Make sure we have better communication with Maintenance Control and read the procedure we are doing at the same as the Controller.
Maintenance Technician performed incorrect MEL (Minimum equipment List) on B737-700 aircraft under direction of Maintenance Control.