故障现象:在电视机的音量开的很小时,图象和伴音都正常;当音量开的较大时,屏幕上出现随声音大小而变化的干扰横条,并引起光栅扭动和折边。检查与排除:开机检查主要部位的直流工作电压,在音量很小时,均正常。开大音量后,测稳压电路输出B点电压,发现该电压随声音大小而波动。 Symptom: When the volume of the TV is on, the picture and sound are normal. When the volume is on, the disturbing bar that varies with the sound size appears on the screen and causes the grating to twist and fold. Check and eliminate: boot check the main part of the DC voltage, the volume is small, are normal. Turn on the volume, the measured voltage regulator circuit output voltage B, found that the voltage fluctuations with the size of the sound.