Narrative:

Working a deferred item for the center-1 (C-1) hydraulic pump [that was] inoperative. Two mechanics involved; I was operating systems from the flight deck and my partner was at the C-1 pump. Using wiring diagram manual (wdm) chapter 29-11-32 for reference; trouble shot system by replacing several relays. Eventually found shorting wiring aft of pump connector. I cannot recall if the [circuit] breakers in the flight deck were already reset; but I looked over flight deck and no breakers were tagged out. After operational check of system; the deferred placard was removed from the [C-1] pump switch. I was unaware of the deactivation of the hydraulic motor pump (hmg) and cleared deferral; thinking resetting all [circuit] breakers and removing placard [would] suffice. I was assigned multiple jobs that night and after completion I was on to the next job. I usually clear all my write-ups after all jobs assigned are fixed [completed]. Aircraft went in for an a-check and hmg was found deactivated. After reactivation [of hmg]; system checked 'ok'.

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Original NASA ASRS Text

Title: Two line mechanics report they failed to notice a Hydraulic Motor Generator (HMG) had been deactivated as part of an MEL Procedure for deferring the Center-1 (C-1) Hydraulic System electric pump on an ETOPS B767-300 aircraft. They had repaired a shorted wire affecting the C-1 pump and cleared the deferral without reactivating the HMG.

Narrative: Working a deferred item for the Center-1 (C-1) Hydraulic Pump [that was] inoperative. Two mechanics involved; I was operating systems from the flight deck and my partner was at the C-1 pump. Using Wiring Diagram Manual (WDM) Chapter 29-11-32 for reference; trouble shot system by replacing several relays. Eventually found shorting wiring aft of pump connector. I cannot recall if the [circuit] breakers in the flight deck were already reset; but I looked over flight deck and no breakers were tagged out. After operational check of system; the deferred placard was removed from the [C-1] pump switch. I was unaware of the deactivation of the Hydraulic Motor Pump (HMG) and cleared deferral; thinking resetting all [Circuit] breakers and removing placard [would] suffice. I was assigned multiple jobs that night and after completion I was on to the next job. I usually clear all my write-ups after all jobs assigned are fixed [completed]. Aircraft went in for an A-Check and HMG was found deactivated. After reactivation [of HMG]; system checked 'OK'.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.