REASON FOR OCCURRENCE:① THE CIRCUIT IS NOT WORKING PROPERLY② INSUFFICIENT BATTERY POWER③ CORROSION OF BATTERY JOINTS OR LOOSE CABLE CONNECTIONS④ POOR CABLE CONNECTION OR CHARGER OR BATTERY FAILURE⑤ STARTING MOTOR MALFUNCTION⑥ CONTROL SCREEN STARTUP CIRCUIT MALFUNCTION⑦ OTHER POSSIBLE MALFUNCTIONS REPAIR METHOD:① CHECK THE CIRCUIT② CHARGE THE BATTERY AND REPLACE IT IF NECESSARY③ CHECK THE TERMINAL POSTS OF THE CABLES, TIGHTEN THE NUTS, AND REPLACE THE SEVERELY CORRODED CONNECTORS AND NUTS④ CHECK THE CONNECTION BETWEEN THE CHARGER AND THE BATTERY⑤ SEEKING HELP⑥ CHECK THE START/STOP CONTROL CIRCUIT OF THE CONTROL SCREEN