1. Abnormal degaussing circuit: image color disorder or partial spots;
2. Abnormal rectifier and filter circuit: three no faults: the capacity of the filter capacitor decreases, which will superimpose interference on the image and sound, and even damage the switch tube;
3. The output circuit of switching oscillation and voltage stabilization is abnormal: there is a "squeak" sound after booting or a degaussing sound of "cha" can be heard after booting, and the next three are no;
4. The switching tube start-up circuit or the filter capacitor capacity of the sampling circuit decreases: three no faults;
5. Abnormal sampling circuit: the main voltage rises randomly, but the protection circuit is not perfect or does not work, then the image suddenly becomes brighter and the color becomes lighter. high;
