This TV set repair many times by others, again 3 without fault, measuring pipe Q501 damage. After change into the new manager on the collector series A 0.5 A fuse tube, after startup, television images, voice, that is normal, but over A period of time (4 to 5 seconds) after the fuse blew out. Analysis inspection: check the power supply voltage is normal, TV immediately after the change the new fuse base voltage measurement manager, found that b voltage from 0.1 V to 0.6 V and blow a fuse, according to the above method can judge the fault is caused by lack of line drive, carefully check the circuit board, found that line driver transformer T502 primary cracks have appeared on pin solder joint will repair welding joint and no longer be blow a fuse, troubleshooting.GuNservice manual download site