Q403 c voltage measured with the same voltage IC451 ② feet , and Q403 b voltage is more stable 0.5V, initially suspected 0403 c, e pole leakage, but remove the measurements were normal. After removal Q403 Q403 c voltage electricity pole measuring board is still beating India . Suspect IC45l ② feet internal circuit damage, after disconnecting the pin , horizontal grating a bright line, but the voltage Q403 c pole at the Indian plate is still beating. Analysis of the circuit in Figure l , when the Q403 c pole and IC451 ② feet off , where the voltage by the resistors R405, R406, R452, R453 partial pressure decision. Taking into account the resistance of the resistor appears less likely unstable dramatic changes , so the suspect repair switch S601 ①, ④ feet between leakage . Try disconnecting S601 ① feet, pull the voltage at Q403 c pole India has stabilized.WV7service manual download site

    Remove S601 measured with a multimeter Rxl0 block between their feet and ① ②, ④ feet are small and unstable resistance . For maintenance switch is rarely used in maintenance , in order to avoid leaving future risks, so it is removed and the original short route ②, ④ footprints board connectivity . After the restitution of other circuits , test machine troubleshooting.WV7service manual download site

 2   Home Previous 1 2