Panasonic NN-K584SF Service Manual page 54

14.3. Digital programmer circuit troubleshooting guide
SYMPTOM
No display when oven is first plugged in.
Oven is dead.
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, 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, 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.
No key input
No beep sound
Power relay A(RY-2) does not turn on
even though the program has been set
and the start pad is tapped
No microwave oscillation at any power
setting
Dark or unclear display
Missing or lighting of incorrect segment
H97/H98 appears in window and oven
stops operation. Program High power for
1 minute and conduct following test
quickly, unless H97/H98 appears and
oven stops. NEW H.V.
CONTINUED FOR SENSOR MODELS
Auto sensor cooking does not operate
normally.
(Steam Sensor cooking does not
detect steam from foods.)
STEP CHECK
1 Fuse pattern of DPC
2 Low voltage transformer (LVT)
secondary voltage
3 IC-1 pin 16 voltage
(Emitter of Q11)
1 Membrane switch continuity
1 IC-1 pin 29 voltage
1 IC-1 pin 9 voltage while
operation
2 Short circuit between collector
and Emitter of Q223.
1 IC-1 pin 7 and pin 34 voltages
while operation at high power
2 Q220 transistor
1 Replace display and check
operation
1 Replace IC-1 and check
operation
1 Unplug CN702(2 pin)
connector and measure
voltage between terminals
2 Unplug CN701(3 pin)
connector and measure pin 1
voltage
1 Steam sensor terminal voltage
by using high impedance
tester (20k Ω/ V),while
breathing on metal surface of
sensor
29
NN-G463 / NN-S443 / NN-S423 / NN-S413 / NN-413
RESULT CAUSE/CORRECTIONS
Normal STEP 2
Open (NOTE) Shorted Circuit of
ZNR,L.V.T., Oven Lamp
etc.Replace DPC
Abnormal 0V LVT
→ Step 3
Normal
Abnormal ZD11, Q11
Normal = 5V Display
Abnormal Membrane switch
Normal IC-1
Abnormal IC-1
Normal BZ, Q224
Abnormal IC-1
→ Step 2
Normal = 5V
Still does not turn on RY-2
RY-2 turns on Q223
Abnormal IC-1
→ Step 2
Normal
7---5V
Abnormal Q220
Normal RY-1
Normal DISPLAY
Abnormal IC-1
Normal IC-1
Abnormal DISPLAY
0V 1. Latch Switch
2. DPC/Power Relay
→ Step 2
AC line voltage of 120V
0V DPC
Approx. AC 3V Magnetron
Abnormal = 0V Steam sensor
Normal>10-30mV IC-1