What was found
SEVERAL CABIN EMERGENCY LIGHTS FAILED PREFLIGHT EMERGENCY LIGHT TEST. MISSING ALL MAIN ENTRY LIGHTS UPPER AND LOWER, FORWARD READING LIGHTS AND HALF OF THE LEFT FORWARD FLOOR LIGHT. RAN APU TO COMPLETE THE REST OF PREFLIGHT. AFTER SHUT DOWN TESTED AGAIN AND SAME LIGHTS STILL FAILED. AFTER SHUT DOWN TESTED AGAIN AND SAME LIGHTS STILL FAILED.REMOVED FAILED #1 BATTERY PACK FUSE PN: S2565-5 AND INSTALLED OPS CHECKS GOOD IAW AMM 33-50-10.