Narrative:

In addition to many other aircraft, I performed maintenance on aircraft X. The aircraft arrived with a deferred item for the yellow hydraulic pump running continuously. I troubleshot the system per the troubleshooting manual and schematics and replaced a time-delay relay for the fix. I then performed a satisfactory functional check of the auxiliary yellow hydraulic system that was failing earlier. All checked good and I then signed off the item. On jul/tue/04, a fellow amt in ZZZ1 found one of the yellow electric pump circuit breakers out -- assuming that it was left out when my deferred item was fixed. It was reset and entered into the aircraft history. The night I worked on that system I did read the MEL deactivation/reactivation procedures. However, there is a possibility that I missed resetting that particular breaker. This is a possibility because the breaker in question only pwrs the system when external power is attached but not selected on the aircraft. All other sits (i.e. Aircraft pwred normally) would work fine through the other 'normal' circuit breaker. The functional check would still have passed with the breaker pulled. The system still worked satisfactorily and no in-flight events occurred. The breaker was found out visually, and reset putting the aircraft back in its normal confign. Doubtful, but if in fact I did inadvertently leave out this circuit breaker, I suppose I would attribute it to the fact that there was a heavy workload and I often work many aircraft and system simultaneously. I will have to slow down a little and ensure that every detail is covered.

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Original NASA ASRS Text

Title: A319 MECH WAS NOT SURE THAT ALL CIRCUIT BREAKERS WERE RESET AFTER WORKING ON THE YELLOW HYD SYS.

Narrative: IN ADDITION TO MANY OTHER ACFT, I PERFORMED MAINT ON ACFT X. THE ACFT ARRIVED WITH A DEFERRED ITEM FOR THE YELLOW HYD PUMP RUNNING CONTINUOUSLY. I TROUBLESHOT THE SYS PER THE TROUBLESHOOTING MANUAL AND SCHEMATICS AND REPLACED A TIME-DELAY RELAY FOR THE FIX. I THEN PERFORMED A SATISFACTORY FUNCTIONAL CHK OF THE AUX YELLOW HYD SYS THAT WAS FAILING EARLIER. ALL CHKED GOOD AND I THEN SIGNED OFF THE ITEM. ON JUL/TUE/04, A FELLOW AMT IN ZZZ1 FOUND ONE OF THE YELLOW ELECTRIC PUMP CIRCUIT BREAKERS OUT -- ASSUMING THAT IT WAS LEFT OUT WHEN MY DEFERRED ITEM WAS FIXED. IT WAS RESET AND ENTERED INTO THE ACFT HISTORY. THE NIGHT I WORKED ON THAT SYS I DID READ THE MEL DEACTIVATION/REACTIVATION PROCS. HOWEVER, THERE IS A POSSIBILITY THAT I MISSED RESETTING THAT PARTICULAR BREAKER. THIS IS A POSSIBILITY BECAUSE THE BREAKER IN QUESTION ONLY PWRS THE SYS WHEN EXTERNAL PWR IS ATTACHED BUT NOT SELECTED ON THE ACFT. ALL OTHER SITS (I.E. ACFT PWRED NORMALLY) WOULD WORK FINE THROUGH THE OTHER 'NORMAL' CIRCUIT BREAKER. THE FUNCTIONAL CHK WOULD STILL HAVE PASSED WITH THE BREAKER PULLED. THE SYS STILL WORKED SATISFACTORILY AND NO INFLT EVENTS OCCURRED. THE BREAKER WAS FOUND OUT VISUALLY, AND RESET PUTTING THE ACFT BACK IN ITS NORMAL CONFIGN. DOUBTFUL, BUT IF IN FACT I DID INADVERTENTLY LEAVE OUT THIS CIRCUIT BREAKER, I SUPPOSE I WOULD ATTRIBUTE IT TO THE FACT THAT THERE WAS A HVY WORKLOAD AND I OFTEN WORK MANY ACFT AND SYS SIMULTANEOUSLY. I WILL HAVE TO SLOW DOWN A LITTLE AND ENSURE THAT EVERY DETAIL IS COVERED.

Data retrieved from NASA's ASRS site as of July 2007 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.