Panasonic NN-K593MF Service Manual

CAUTION NEW. H.V.1. High voltage is present at the high voltage terminal of the HighVoltage Inverter (U) including aluminum heat sink during any cookcycle.2. It is neither necessary nor advisable to attempt measurement of thehigh voltage.3. Before touching any oven components, or wiring, always unplugthe oven from its power source and discharge the high voltagecapacitors.6.1. Primary latch switch(Secondary latch switch andpower relay B) interlocks.1. Unplug the lead connectors to Power Relay B and verifycontinuity of the power relay B 1-2 terminals.2. Unplug lead connectors to Primary Latch Switch andSecondary Latch Switch.3. Test the continuity of switches at door opened and closedpositions with ohm meter (low scale).Normal continuity readings should be as follows.6.2. Short switch & monitor1. Unplug lead wires from Inverter Power Supply (U) primaryterminals.2. Connect test probes of ohm meter to the disconnectedleads which were connected to Inverter Power Supply (U).3. Test the continuity of short switch with door opened andclosed positions using lowest scale of the ohm meter.Normal continuity readings should be as follows.6.3. MagnetronContinuity checks can only indicate an open filament or ashorted magnetron. To diagnose for an open filament orshorted magnetron.1. Isolate magnetron from the circuit by disconnecting theleads.2. A continuity check across magnetron filament terminalsshould indicate one ohm or less.3. A continuity check between each filament terminal andmagnetron case should read open.6.4. Membrane key board(Membrane switch assembly)Check continuity between switch terminals, by tapping anappropriate pad on the key board. The contacts assignment ofthe respective pads on the key board is as shown in digitalprogrammer circuit.6 COMPONENT TEST PROCEDURE15NN-S453WF