What was found
AIRCRAFT WAS NOT GROUNDED: AT THE GATE BEFORE FLIGHT, THE FUEL QUANTITY INDICATED 8500 IN EACH MAIN TANK (BALANCED CONDITION) AND 3700 IN THE CENTER TANK. AFTER ENGINE START, THE LEFT TANK INDICATED ONLY 7200 AND THE AMBER IMBALANCE ANNUNCIATION ILLUMINATED. ALMOST 1500 OF FUEL ARE UNACCOUNTED FOR. AIRCRAFT RETURNED TO THE GATE. LEFT HAND WING FUEL QUANTITY INDICATION CONFIRMED INOPERATIVE **SUPPLEMENTAL REPORT FOR (AALA202501105255): PERFORMED CAP AND RESISTANCE DRY TESTS, PER B737 AMM 28-41-21-710-801. ALL READINGS WITHIN LIMITS BUT NOT LO/2 TO HI/2 FLUCTUATING READINGS AT TANK UNIT 5 AND 6 COMPENSATOR. REMOVED AND REPLACED TANK 5 COMPENSATOR (AALA202501105255) AND TANK 6 COMPENSATOR (AALA202501151248), PER AMM 28-41-21. OPERTIONAL AND BITE CHECKS GOOD. NO FAULTS**(CLOSED).