Panasonic 1100W - Sharp 1 CF Microwave Service Manual

1. Check grounding before checking for trouble.2. Be careful of high voltage circuit.3. Discharge high voltage capacitor.4. When checking the continuity of the switches or the high voltage transformer,disconnect one lead wire from these parts andthen check continuity with the AC plug removed. To do otherwise may result in a false reading or damage to your meter.When disconnecting a plastic connector from a terminal, you must hold the plastic connector instead of the lead wire andthen disconnect it, otherwise lead wire may be damaged or the connector cannot be removed.5. Do not touch any parts of the circuitry on the digital programmer circuit, since static electric discharge may damage thiscontrol panel.Always touch yourself to ground while working on this panel to discharge any static charge in your body.6. 120V AC is present on the digital programmer circuit (Terminals of power relay’s and primary circuit of low voltagetransformer). When troubleshooting, be cautious of possible electrical shock hazard.1. Oven is dead.Fuse is OK.No display and no operation at all.2. No display and no operation at all.Fuse is blown.3. Oven does not accept key input(Program)4. Fan motor turn on when oven isplugged in with door closed.1. Key input is not insequence2. Open or loose connection of membrane key padto DPC (Flat cable)3. Shorted or open membrane key board4. Defective DPC1. Misadjustment or loose wiring of secondarylatch switch2. Defective secondary latch switch1. Off-alignment of latch switches2. Open or loose connection of high voltage circuitespecially magnetron filament circuitNOTE: Large contact resistance will bring lowermagnetron filament voltage and causingmagnetron to lower output and/or be in-termittent.3. Defective high voltage componentHV Inverter Power Supply (u)Magnetron4. Open or loose wiring of power relay B (RY-1)5. Defective primary latch switch6. Defective DPC or power relay B (RY-1)1. Open or loose wiring of secondary latch switch2. Off-alignment of secondary latch switch3. Defective secondary latch switch1. Decrease in power source voltage2. Open or loose wiring of magnetron filamentcircuit.(Intermittent oscillation)3. Aging change of magnetron1. Shorted primary latch switchCheck fan motor when thermal cutout is defective.Check adjustment of primary, secondary latchswitch and short switch including door.TROUBLESHOOTING GUIDECAUTIONFirst of all operate the microwave oven following the correct operating procedures in order to find the exact cause of any trouble.SYMPTOM CAUSE CORRECTIONSRefer to operation procedure.Refer to DPC troubleshooting.Adjust door and latch switches.Adjust door and latch switches.Check high voltage component according to com-ponent test procedure and replace if it is defective.Refer to DPC troubleshootingAdjust door and latch switches.1. Open or loose lead wire harness2. Open thermal cutout (Cavity)3. Open low voltage transformer4. Defective DPC1. Shorted lead wire harness2. Defective primary latch switdh (NOTE 1)3. Defective short switch (NOTE 1)4. Defective Inverter Power Supply (U) (Page 18)NOTE 1: All of these switches must be replaced at the same time.Check continuity of power relay (RY1)’s contacts (between 1 and 2) and if it has continuity,replace power relay B (RY-1)’s.5. Timer starts count down but no microwave oscil-lation.(No heat while oven lamp and fan motor turn on)6. Oven can program but timer does not start count-down.7. Microwave output is low. Oven takes longer timeto cook food.8. Fan motor turns on and turntable rotates whendoor is opened.Consult electrician- 20 -