Panasonic NN-K593MF Service Manual

9 TROUBLESHOOTING GUIDEDANGER HIGH VOLTAGES1. DO NOT RE-ADJUST PRESET CONTROL on the H.V.Inverter (U). It is very dangerous to repair or adjust without sufficient test equipmentbecause this circuit handles very large current and high voltage. Operating a misaligned inverter circuit is dangerous.2. Ensure proper grounding before checking for trouble.3. Be careful of the high voltage circuitry, taking necessary precautions when troubleshooting.4. Discharge high voltage remains in the H.V.Inverter (U).5. When checking the continuity of the switches or the H.V.Inverter, disconnect one lead wire from these parts and then check continuity with theAC plug removed. To do otherwise may result in a false reading or damage to your meter. When disconnecting a plastic connector from aterminal, you must hold the plastic connector instead of the lead wire and then disconnect it, otherwise lead wire may be open or the connectorcannot be removed.6. Do not touch any parts of the circuitry on the digital programmer circuit, since static electric discharge may damage this control panel. Alwaystouch yourself to ground while working on this panel to discharge any static charge in your body.7. 230-240V AC is present on the digital programmer circuit (Terminals of power relay’s and primary circuit of Digital Programmer Circuit). Whentroubleshooting, be cautious of possible electrical shock hazard.Before troubleshooting, operate the microwave oven following the correct operating procedures in the instruction manual in orderto find the exact cause of any trouble, since operator error may be mistaken for the oven’s malfunction.9.1. (Trouble) Oven stops operation during cookingSYMPTOM CAUSE CORRECTIONS1. Oven stops in 3 seconds afterpressing start padNo 230-240V AC is supplied to H.V.Inverter (U)CN702 terminals1. Latch Switch2. Power relay RY-13. Loose lead wire connector CN701, CN702Oven stops in 23 seconds afterpressing start padH.V.Inverter (U) operates by the control signalsfrom DPC but magnetron is not oscillating1. Magnetron2. Loose lead wire connector CN703Oven stops in 10 seconds afterpressing start pad(Auto sensor cooking)Steam sensor circuit does not function 1. Steam sensor2. DPC3. Loose wiring connector CN22. No display and no operation at all.Fuse is blown.Most probably loose connection of connectors ordoor latch mechanism is not adjusted properly1. Allign door, Door Latch Switches2. Loose wiring connectors19NN-S453WF