Panasonic NN-S560BF, NN-S560WF, NN-L530BF Trouble Related to Digital Programmer Circuit

Trouble Related to Digital Programmer Circuit

SYMPTOM	STEP	CHECK	RESULT	CAUSE/CORRECTIONS
No display when oven is first plugged in.	1	Fuse pattern of DPC	Normal	STEP 2
Oven is dead.			Open (NOTE)	Shorted Circuit of ZNR,
				L.V.T., Oven Lamp etc.
				Replace DPC
	2	Low voltage transformer (LVT)	Abnormal 0V	LVT
		secondary voltage	Normal	➝ Step 3
	3	IC-1 pin 8 voltage	Abnormal	ZD10, Q10
		(Emitter of Q10)	Normal = 5V	➝ Step 4
	4	IC-1 pin 10 voltage	Abnormal	IC-220
		(15 pin of IC-220)	Normal	➝ IC-1, CX320

NOTE

Procedure of fuse pattern repairing is as follows:

1. When the fuse pattern (PF2) opens.

(1) Remove the jumper wire (PF1).

(2) Insert the removed jumper wire (PF1) to “(PF2)” position and solder it. If both “PF1” and “PF2” fuse patterns are open, please replace DPC.

2. When the fuse pattern (PF4) opens.

(1) Remove the jumper wire (PF3).

(2) Insert the removed jumper wire (PF3) to “(PF4)” position and solder it. If both “PF3” and “PF4” fuse patterns are open, please replace DPC.

NOTE:* At the time of these repairs, make visual inspection of the varistor for burning damage and examine the transformer with tester for the presence of layer short- circuit (check primary coil resistance).

If any abnormal condition is detected, replace the defective parts.

SYMPTOM		STEP	CHECK	RESULT	CAUSE/CORRECTIONS
No key input		1	Membrane switch continuity	Abnormal	Membrane switch
				Normal	IC-1
No beep sound		1	IC-1 pin 31 voltage	Abnormal	IC-1
				Normal	BZ, IC-220
Power relay A(RY-2) does not turn on		1	IC-1 pin 32 voltage while operation	Abnormal	IC-1
even though the program has been set				Normal = 5V	➝ Step 2
and the start pad is tapped		2	Short circuit between pin 6 and pin	Still not turn on	RY-2
			16 of IC-220	RY-2 turns on	IC-220
No microwave oscillation at any power		1	IC-1 pin 38 and pin 39 voltages while	Abnormal	IC-1
setting			operation at high power
				Normal	➝ Step 2
				5---5V, 15---5V
		2	Q220 transistor	Abnormal	Q220
				Normal	IC-220, RY-1
Dark or unclear display		1	Replace display and check operation	Normal	DISPLAY
				Abnormal	IC-1
Missing or lighting of unnecessary		1	Replace IC-1 and check operation	Normal	IC-1
segment				Abnormal	DISPLAY
H97/H98 appears in window and oven		1	Unplug CN702(2 pin) connector and	0V	1. Latch Switch
stops operation. Program High power			measure voltage between terminals		2. DPC/Power Relay
				AC line voltage of 120V	➝ Step 2
for 1 minute and conduct following test
quickly, unless H97/H98 appears and		2	Unplug CN701(3 pin) connector and	0V	DPC
oven stops.			measure pin 1 voltage	Approx. AC 3V	Magnetron
	NEW H.V.

TO BE CONTINUED FOR SENSOR MODELS

Auto sensor cooking does not operate	1	Steam sensor terminal voltage by	Abnormal = 0V	Steam sensor
normally.		using high impedance tester (20k Ω/
			Normal > 10~30mV	IC-1
(Steam Sensor cooking does not detect		V), when breathe on metal surface of
steam from foods.)		sensor

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