Panasonic NN-ST678S Microwave Oven User Manual


 
8.4. 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: Ammeter reading is: To do: Remedy:
Shut off in 37 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(F606Y8M00AP)
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.
8.5. H.V.INVERTER BOARD MAIN PARTS LIST (F606Y8M00AP)
Ref. No. Part No. Part Name & Description Pcs/Set Remarks
DB701 B0FBBS000001 BRIDGE DIODE 1 20A, 600V
L701 F50206G00AP CHOKE COIL 1
Q701 B1JAGV000015 TRANSISTOR SI 1 1000V
T701 A609A8M00AP H.V. TRANSFORMER 1 (INCLUDING D701,D702,C706,C707)
C701 ECWF5284N300 CAPACITOR 1 0.28µF/500V
C702 ECWF2455N644 CAPACITOR 1 4.5µF/250V
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NN-SD698S / NN-ST678S / NN-ST658W