Access VCD test machine, normal. Referring to Beijing 2101C circuit drawings, there is sound, indicating that there is no problem in the amplifier circuit, fault coverage is determined in N101 (LA7680) 42 feet (video signal output) to AV / TV converter circuit N801 (LC4066) between 11 and ④ feet , as shown in Figure 1. First press the AV / TV converter key measure N801's ⑤, ⑥, ⑩ feet have a normal high-low, indicating that the normal CPU instruction control. In the TV status, with a 10μF capacitor connected around 30cm piece of wire, one end soldered V802's b-pole, the other end touch N10l of 42 feet, the image appears to continue in the future touch R123, RPl21 upper end, there is an image appears. When touched midpoint RPl21, there is no change on the screen, it is clear that the problem lies in the RPl21. Examination revealed RPl21 midpoint open, put a 1kΩ potentiometer, the image properly. With this example, a capacitor repair faulty components quickly found the same for the other signal channel can use this method to find the point of failure.28Bservice manual download site