B737-700
Maintenance Powerplant; Maintenance Airframe
Troubleshooting; Time Pressure; Situational Awareness; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
General Flight Cancelled / Delayed; General Maintenance Action
Human Factors; MEL; Procedure; Aircraft
On Date; around XA:00-XB:00; quick turn Aircraft X arrived at gate XX with a speed brake issue. I took upgrade lead that day. I assisted the mechanics dispatching those gates by MEL'ing the speed brakes due to history and no time to troubleshoot as it was a live flight. As I was lead that day and needed to understand what exactly was being done/MEL'd;  I flipped over looking at both MELs that would be required to make sure we had the correct MELs and were proceeding accordingly. As documented; I proceeded with MEL XX-YY-B; verifying manual speed brake system operated normally REF Step A. 1-4 per MEL CARD XXXXX (XX-YY-B). As another mechanic was creating/proceeding with the 2nd deferral; I mistakenly thought the breaker MEL XX-YY-B stated to open; and the breaker he was opening for MEL XX-YY-A were the same breaker. He collared the breaker; we installed placards; and the airplane left. Upon review of the MEL; I realized the MELs do not state to open the same breaker; and the breaker he had collared was not the breaker I thought was being collared. So Step B of MEL XX-YY-B did not get completed and the MEL was not in compliance.
Lead Technician reported non compliance with MEL procedures on a transit aircraft was noticed after records review and were corrected.