Observation fans, lights , trays, light and other operating normally , no abnormal sounds and different ignorant , panels of various instructions properly. Preliminary analysis of the control system is intact, the fault in the main loop.ga9service manual download site
 ga9service manual download site

    The figure shows that , if the fan power , lights , trays , so light in normal operation , the primary circuit of the transformer T is good , the fault in the high pressure circuit. Open the case , the test parameters for each component in case of power outages as follows :ga9service manual download site

    Magnetron filament resistance to O. 9Ω ( normal resistance 1Ω or less ); T primary winding resistance of 2.8Ω ( normal 2Ω ~ 3Ω); T secondary voltage winding resistance is 82n ( normal 80Ω ~ 100Ω); voltage capacitor capacity 1.01μF ( the nominal size is 1μF/2100V); hypertension Insurance resistance 0Ω; connecting wires between the resistor element O. 4Ω or less .ga9service manual download site

    Looking at the results from the measurement seems to be no problem , the only high voltage can not be determined whether the damage to the diode D , as the forward breakdown voltage is extremely D ordinary multimeter inaccurate measurements. After the D series with a lamp 40W/220V access to electricity , dim light bulb to determine D is good. All high-voltage components are intact , the problem is where?ga9service manual download site

    Electricity, measured magnetron cathode filament voltage of 3.2V, high voltage transformer primary voltage of 225V, the parameters are normal , only microwave input current is 5.7A and slow growth , with nominal 8.3A greater access . Here overhaul stalled , only using the substitution method . The high-pressure insurance, high voltage diodes, high voltage capacitors , magnetrons , transformers eleven substitution, but the symptoms remained unchanged. When the input current is observed at the edge of each side shaking connecting wires , found that the current high-voltage capacitor and magnetron connected with wires shaking fluctuate , then carefully observed this power wire , found magnetron end of the wire clamp plastic sheath opening slightly yellow, open catch and some loose wires , welding firm after the test machine , everything is normal.

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