With R * 1 block of cold resistance measurement of transformer primary winding: usually 1.5 ~ 3; the secondary high-voltage winding is 80 ~ 150; filament winding is close to 0. Use megohmmeter (50OV insulation resistance meter) or with a multimeter measuring R * 10K block, the primary and secondary of the transformer shell resistance greater than lOOM. If the resistance is obviously less than the normal value, the transformer leakage. Measurement should pay attention to remove insulation transformer shell on the measured position, ensure good contact with the shell pen. At the same time not both contact to the conductive parts in contact with the pen and the measuring point, otherwise the pointer indicator may be the human body resistance smaller, instead of transformer insulation resistance. Similarly, the multimeter is used to measure high voltage capacitor, high voltage diodes and other components as well as to pay attention to this point.Xx3service manual download site
Common faults of high voltage transformer are mainly:Xx3service manual download site
(1) the bad contact wire, winding or circuit breaker. This will cause the microwave oven is not heated or unstable work etc.. (2) high voltage winding internal short circuit, winding and casing leakage or short circuit. This will cause the microwave oven doesn't work, burning fuse or unstable work etc.. For (1) can check the wire and connector, if broken, as long as the re welding or connecting firm can; if bad, should remove dirt, and strengthen the contact fastness can be both. For (2) can usually roasted or re wound, if after baking not or cannot rewind, it should be changed to a new one.Xx3service manual download site