What was found
(CAN) APU CHARGER STATUS MESSAGE POSTED - CIRCUIT BREAKER POPPED - NO TAXI OUT. WHEN MECHANIC RESET THE C/B THE CONNECTOR PLUG ON TOP OF THE CHARGER CAUGHT FIRE.REPAIRED CONNECTOR PLUG BY REPINNING AND ASSOCIATED WIRES. REPLACED APU BATTERY & CHARGER. AFFECTED COMPONENTS: APU BATTERY CHARGER + BATTERY + CONNECTOR P12PA. BATTERY P/N 4078-3, S/N 082634, TSN: 252 HOURS & 254 CYCLES. CONNECTOR P/N MS27473T14B18S.