B737-800
Maintenance Airframe; Maintenance Avionics; Maintenance Powerplant
Maintenance Avionics 43; Maintenance Technician 43
Communication Breakdown; Distraction; Time Pressure; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy
Human Factors; Procedure
[I received] a pilot call for relamping First Officer's FMC annunciator. Relamping was no help so I conducted a flight control system fault check. I noticed that the left FCC had a fault. After I reset the circuit breaker; the FMC annunciator started to work. [In order] to explain this to the Captain and First Officer I had to [position] the test switch (autopilot disengage) in disengage position and FMC switch on overhead on both on left and do the test again because they were not sure that they wanted to fly this airplane. I left assuming that the pilot saw the switches in test position and would restore them back to normal. All the correct positions of all switches on the overhead and on the center pedestal should be covered by the checklist. Otherwise if any switches are in the wrong position [this will] cause a problem.
A Maintenance Technician repositioned switches in the flight deck to conduct a test procedure; and assumed that the pilots would recognize it and change them back to the normal position.