What was found
APU FAILED STARTS. ACCOMPLISHED TEST AND APU FAILED INITIAL START TEST WITH MASTER SW TO START: FUEL SOL LT, IGNIT FUEL DIV, DE-OIL, BLEED RELAY LOP & HOT NEVER CAME. STATIC CHECK RES CHECKED OK. ACCOMPLISHED TEST WITH APU TESTER IAW MM AND APU FAILED INITIAL START UP TEST WITH MASTER SW TO ON APU WOULDN`T CRANK. REPLACED IGNITER PLUG AND EXCITER BOX, INSPECTED CHIP DETECTORS FOUND NO METAL, APU STARTED NORMAL 3 TIMES, ENGINE STARTS AND PACK OPS NORMAL.