Panasonic NN-ST65JB, Руководство по обслуживанию

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7.4. Trouble related to Digital Programmer Circuit
SYMPTOM STEP CHECK RESULT CAUSE/CORRECTIONS
No display when oven is first plugged
in 1 Fuse pattern of D.P.C., FUSE1 Normal
→
Step2
Open Replace D.P.C. or Fuse Pattern
or FUSE
2 Low voltage transforment (L.V.T.)
secondary voltage Abnormal 0V L.V.T. (T10)
Normal
→
Step3
3 IC1 pin 13 voltage Abnormal IC10
Normal=5V IC1, Display
No key input 1 Membrane switch continuity Abnormal Membrane switch
Normal IC1
No beep sound 1 IC1 pin 49 voltage Abnormal IC1
Normal=5V BZ210, Q210
No microwave oscillation at any power 1 IC1 pin 50 voltages while operation at high
power Abnormal IC1
Normal=5V
→
Step2
2 Collector of Q227 voltage Abnormal Q227 and/or Q225, Q226
Normal 0.7V
→
Step3
3 Short circuit between collector of Q227
and emitter of Q225 Still not turn on RL1
RL1 turns on Q227 and/or Q225, Q226
Dark or unclear display 1 Replace display and check operation Normal Display
Abnormal IC1
Missing or lighting of unnecessary
segment 1 Replace IC1 and check operation Normal IC1
Abnormal Display
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 1 Unplug CN702 (2 pin) connector and
measure voltage between terminals Abnormal=0V 1. Interlock Switch
2. D.P.C. /Power Relay
Normal=220/240V
→
Step2
2 Unplug CN701 (3 pin) connector and
measure pin1 voltage Abnormal=0V D.P.C.
Approx. AC 3V Magnetron
7.5. Simple way of H.V. Inverter/magnetron troubleshooting
Purpose:
Simple way (3/23 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: Ammeter reading is: To do: Remedy:
Shut off in 23 seconds
after “Start”. 1. Between 0.5A and 1.0A. Check and repair open magnetron circuit Open magnetron wiring between Inverter
and magnetron terminal.
2. Between 1.0A and 2.0A. Check continuity of D702 in Inverter PCB.
1. D702 shorted Replace H.V.Inverter
(F606YBA00GP)
2. D702 is OK Replace magnetron
Shut off in 3 seconds
after “Start” 1. Less than 0.5A Check open circuit: Latch Switch, DPC,
Power Relay and CN701 Replace defective component(s), or
correct switch, cables and connectors.
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NN-ST65JM / NN-ST65JB