Panasonic NN-S560BF, NN-S560WF, NN-L530BF service manual Troubleshooting Guide

TROUBLESHOOTING GUIDE

CAUTION

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 and then 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 and then 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 this control 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 voltage transformer). When troubleshooting, be cautious of possible electrical shock hazard.

First of all operate the microwave oven following the correct operating procedures in order to find the exact cause of any trouble.

	SYMPTOM		CAUSE	CORRECTIONS
1.	Oven is dead.	1.	Open or loose lead wire harness	Check fan motor when thermal cutout is defective.
	Fuse is OK.	2.	Open thermal cutout (Cavity)
	No display and no operation at all.	3.	Open low voltage transformer
		4.	Defective DPC
2.	No display and no operation at all.	1.	Shorted lead wire harness	Check adjustment of primary, secondary latch
	Fuse is blown.	2.	Defective primary latch switdh (NOTE 1)	switch and short switch including door.
		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.
3.	Oven does not accept key input(Program)	1.	Key input is not insequence	Refer to operation procedure.
		2. Open or loose connection of membrane key pad
			to DPC (Flat cable)
		3.	Shorted or open membrane key board
		4.	Defective DPC	Refer to DPC troubleshooting.
4.	Fan motor turn on when oven is	1.	Misadjustment or loose wiring of secondary	Adjust door and latch switches.
	plugged in with door closed.		latch switch
		2.	Defective secondary latch switch
5.	Timer starts count down but no microwave oscil-	1.	Off-alignment of latch switches	Adjust door and latch switches.
	lation.	2. Open or loose connection of high voltage circuit
	(No heat while oven lamp and fan motor turn on)		especially magnetron filament circuit
		NOTE: Large contact resistance will bring lower
			magnetron filament voltage and causing
			magnetron to lower output and/or be in-
			termittent.
		3.	Defective high voltage component	Check high voltage component according to com-
			HV Inverter Power Supply (u)	ponent test procedure and replace if it is defective.
			Magnetron
		4.	Open or loose wiring of power relay B (RY-1)
		5.	Defective primary latch switch	Refer to DPC troubleshooting
		6.	Defective DPC or power relay B (RY-1)	Adjust door and latch switches.
6.	Oven can program but timer does not start count-	1.	Open or loose wiring of secondary latch switch
	down.	2.	Off-alignment of secondary latch switch
		3.	Defective secondary latch switch
7.	Microwave output is low. Oven takes longer time	1.	Decrease in power source voltage	Consult electrician
	to cook food.	2.	Open or loose wiring of magnetron filament
			circuit.(Intermittent oscillation)
		3. Aging change of magnetron
8.	Fan motor turns on and turntable rotates when	1.	Shorted primary latch switch
	door is opened.

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