Trouble Related To Digital Programmer Circuit; Simple Way Of H.v. Inverter/Magnetron Troubleshooting - Panasonic NN-CS597S APH Service Manual

10.4. Trouble related to Digital Programmer Circuit

SYMPTOM
No display when oven is first plugged
in
No key input
No beep sound
Power relay RY2 does not turn on
even though the program had been set
and the start button is tapped
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

10.5. SIMPLE WAY OF H.V. INVERTER/MAGNETRON TROUBLESHOOTING

Purpose:
Simple way (3/37 seconds rule) of identifying whether it's Magnetron, Inverter or others.
Set-up:
The unit under question is connected through the Ammeter as shown below.
Procedure:
Follow the matrix table below to identify the problem source.
Note:
Do not replace both Inverter board and Magnetron simultaneously and automatically without going through this
procedure.
Power will:
Shut off in 37 seconds 1. Between 0.5A and 1.0A.
after "Start".
2. Between 1.0A and 2.0A.
Shut off in 3 seconds 1. Less than 0.5A
after "Start".
STEP
1 Fuse pattern of D.P.C.
2 Low voltage transforment (L.V.T.)
secondary voltage
3 IC10 pin5 voltage
1 Membrane switch continuity
1 IC1 pin 8 voltage
1 IC1 pin 22 voltage while operation
2 Collector of Q222 voltage
1 IC1 pin 24 voltages while operation at high
power
2 Collector of Q223 voltage
3 Short circuit between collector and emitter
of Q223
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 pin3 voltage
Ammeter reading is:
Check and repair open magnetron circuit
CN703.
Check continuity of D702 in Inverter PCB.
1. D702 shorted
2. D702 is OK
Check open circuit: Latch Switch, DPC,
Power Relay, CN701 and CN702.
CHECK
Normal
Open
Abnormal 0V
Normal
Abnormal
Normal=5V
Abnormal
Normal
Abnormal
Normal=5V
Abnormal
Normal=5V
Abnormal
Normal 0.7V
Abnormal
Normal=5V
Abnormal
Normal 0.7V
Still not turn on
RY1 turns on
Normal
Abnormal
Normal
Abnormal
Abnormal=0V
Normal=120V
Abnormal=0V
Approx. AC 3V
To do:
33
RESULT CAUSE/CORRECTIONS
→Step2
Replace D.P.C. or Fuse
Pattern
L.V.T.
→Step3
IC10
IC1, CX320, Display
Membrane switch
IC1
IC1
BZ210, Q210
IC1
→Step2
Q222
RY2
IC1
→Step2
Q223
→Step3
RY1, Q227
Q223
Display
IC1
IC1
Display
1. Latch Switch
2. D.P.C. /Power Relay
→Step2
D.P.C.
Magnetron
Remedy:
Open magnetron wiring between Inverter
and magnetron terminal.
Replace H.V.Inverter(F606Y8M00AP)
Replace magnetron
Replace defective component(s),
correct switch, cables and connectors.
NN-CS597S
or