This TV set by others repair times, each fault is the "three noes", for output Q501 damage. For the uplink output tube Q501, television image and voice is restored to normal, but after a period of time, at least 4-5 minutes, much is ten Tianxing output tube Q501 and damaged. Check the power supply output voltage of the TV is normal, no abnormal frequency, retrace capacitance for output is normal. Carefully check the circuit board found that promote transformer T501 secondary pin solder joint cracks, judgment is lack of incentive, caused by burn line output tube. The solder joints after welding, pipe line output Q501 (2SD1554), troubleshooting. Panasonic M12 movement also often encountered the phenomenon of burning line Q651 (2SD1555), the reason for the line to promote the transformer T501 to line output tube Q651 solder joints between the cracks and contact caused by bad.