What was found
DURING GPU ASSISTED ENGINE START, EMER LIGHT NOT ARMED CAS DISPLAYED WHILE THE EMERGENCY LIGHT SWITCH WAS IN FACT IN THE ARMED POSITION. THE EMER LIGHTS WERE ILLUMINATED AND STAYED ON. TURNED BATTERIES OFF FOR 2 MINS PER MAINT REQUEST. SECOND ENG START ON BATTERY-ONLY RESULTED IN THE SAME EMERGENCY LIGHTS STATING ILLUMINATED WITH SWITCH IN ONLY THE ARMED POSITION. POWERED ON ACFT W/ GPU, CONFIRMED W/ ARM POSITION & EMER LIGHTS ACTIVE. INSPECTED EMERGENCY LIGHTS INERTIAL SWITCH. NO DEFECTS NOTED. T/S SYSTEM PER FIM AMM 33-50-00-810-801-A. NR 2 BATTERY. DISCONNECTED P2056 & CYCLED POWER TO EMER LTS AT SWITCH. -DISCONNECTED PILOT & COPILOT SEAT FROM RAIL, DISCONNECTED P2150, ISOLATED ISSUE TO FAULTY EMERGENCY BATTERY PACKS. REMOVED NR 1 BATTERY. INSTALLED NR 1 BATTERY. BATTERY FUNC CHECKED. REMOVED NR 2 BATTERY & INSTALLED #2 REPAIRED BATTERY. BATTERY FUNC CHECKED. PERFORMED A GOOD OPS CHECK. PERFORMED 90 MIN CHARGE. OPS CHECK SATISFACTORY IAW AMM 33-52-01.