Trouble Related To Digital Programmer Circuit - Panasonic NN-SF564S Service Manual

9.4.

Trouble related to Digital Programmer Circuit

SYMPTOM
No display when oven is first plugged
in
No key input
No beep sound
No microwave oscillation at any power
Dark or unclear display
Missing or lighting of unnecessary
segment
H95/H97/H98 appears in window and
oven stops operation.Program High
power for 1 minute and conduct
following test quickly, unless
H95/H97/H98 appears and oven stops
STEP CHECK
1 Fuse pattern of D.P.C.
2 IC10 pin4 voltage
3 IC10 pin5 voltage
1 Touch switch continuity
1 IC1 pin 1 voltage
1 IC1 pin 12 voltages while operation at high
power
2 Collector of Q227
1 Replace display and check operation
1 Replace IC1 and check operation
1 Unplug CN702 (2 pin) connector and
measure voltage between terminals
2 Unplug CN701 (3 pin) connector and
measure pin1 voltage of D.P.C. CN3
21
RESULT CAUSE/CORRECTIONS
→Step2
Normal
Open Replace D.P.C. or Fuse
Pattern
Abnormal 0V IC25
→Step3
Normal=12V
Abnormal IC10
Normal=5V IC1, CX320, Display
Abnormal Touch switch
Normal IC1
Abnormal IC1
Normal=5V BZ210, Q210
Abnormal IC1
→Step2
Normal=5V
Abnormal Q222 and/or Q225, Q227
Normal 0.7V RL1
Normal Display
Abnormal IC1
Normal IC1
Abnormal Display
Abnormal=0V 1. Interlock Switch
2. D.P.C. /Power Relay
→Step2
Normal=120V
Abnormal=0V D.P.C.
Approx. AC 3V Magnetron
NN-SF564S / NN-SF564M