What was found
AIRCRAFT IN BASE MAINTENANCE: LEFT HORIZONTAL STABILIZER ELEVATOR TAB CONTROL MECHANISM HAS MISSING SPRING. INSTALLED NEW LEFT HAND AFT OUTBOARD ELEVATOR TAB CONTROL MECHANISM SPRING AND REINSTALLED LEFT HAND AFT INBOARD ELEVATOR TAB CONTROL MECHANISM SPRING, PER B737NG AMM 27-31-34. PERFORMED SATISFACTORY OPERATIONAL TEST ON LEFT HORIZONTAL STABILIZER ELEVATOR TAB, PER B737NG AMM27-31-00 NO DEFECTS NOTED AT THIS TIME.