background image

7.4. 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

(Z606YBH20GP)

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.

7.5. How to check the semiconductors using an OHM meter

22

NN-CT585S / NN-CT565M / NN-CT555W

Summary of Contents for NN-CT555W

Page 1: ... Panasonic Appliances Microwave Oven Shanghai Co Ltd 2015 NN CT585S NN CT565M NN CT555W BPQ U K Microwave Oven ORDER NO PAPMOSH1502012CE ...

Page 2: ...2 NN CT585S NN CT565M NN CT555W ...

Page 3: ...3 NN CT585S NN CT565M NN CT555W ...

Page 4: ...OCEDURE 16 5 1 Primary Secondary Latch Switch interlocks Power Relay RY1 16 5 2 Short Switch 16 5 3 Magnetron 16 5 4 Inverter power supply U 17 5 5 Temperature thermistor 17 6 MEASUREMENTS AND ADJUSTMENTS 18 6 1 Adjustment of primary latch switch secondary latch switch and short switch 18 6 2 Measurement of microwave output 18 7 TROUBLESHOOTING GUIDE 19 7 1 Troubleshooting Oven stops operation dur...

Page 5: ...digital programer circuit determines the power level and cooking time to complete cooking and indicates the operating state in the display window 2 When cooking time in the display window has elapsed the oven turns off automatically by a control signal from the digital programmer circuit 2 4 Thermistor The thermistor which fixed on magnetron detects magnetron temperature and make power down when t...

Page 6: ...num heat sink may be HOT due to heat energy therefore extreme care should be taken during servicing H V Inverter warning WARNING FOR INVERTER POWER SUPPLY U GROUNDING Check the High Voltage Inverter Power Supply circuit grounding The high voltage inverter power supply circuit board must have a proper chassis ground The inverter grounding plate must be connected to the chassis If the inverter board...

Page 7: ...ring operation Never insert a wire nail or any other metal object through the lamp holes on the cavity or any holes or gaps because such objects may work as an antenna and cause microwave leakage 3 6 Verification after repair 1 After repair or replacement of parts make sure that the screws of the oven etc are neither loosen or missing Microwave energy might leak if screws are not properly tightene...

Page 8: ...n motor bracket on the top plate of the oven 8 Disconnect 2 connectors from oven lamp terminals 9 Remove convection fan motor assembly air guide A 10 Disconnect 2 high voltage lead wires from magnetron filament terminals 11 Remove 4 screws holding the magnetron NOTE After replacement of the magnetron tighten mounting screws properly in an x pattern making sure there is no gap between the waveguide...

Page 9: ...nect all connectors from D P C board DU 2 Disconnect 1 grounding connector 3 Remove 1 screw holding escutcheon base and slide the escutcheon base upward slightly 4 Remove door opening lever 5 Disconnect flat cable CN11 from D P C board AU 6 Release catch hooks on escutcheon base to move over the D P C board AU 10 NN CT585S NN CT565M NN CT555W ...

Page 10: ... of more than 30 watts on D P C contacts B With all the terminal pins cleaned and separated from D P C contacts remove the defective transformer power relays Replace components making sure all terminal pins are inserted completely resolder all terminal contacts carefully 4 4 Fan motor 1 Disconnect 2 lead wires from fan motor terminals 2 Remove 1 screw at location on oven attaching orifice assembly...

Page 11: ...of the door will touch firmly to the oven cavity front plate without pushing the door If the door assembly is not mounted properly microwave power may leak from the clearance between the door and oven NOTE Always perform the microwave leakage measurement test after installation and adjustment of door assembly 4 6 Turntable motor 1 Remove the motor cover by breaking off at the 8 spots indicated by ...

Page 12: ...e heater terminals 4 Remove 2 screws holding heater mounting plate 5 Remove the heater by pulling it out 4 8 Convection fan assembly 1 Remove pulley belt 2 Remove 5 screws holding fan case unit on the oven NOTE After replacement repair of the fan case unit tighten mounting screws properly in an x pattern 13 NN CT585S NN CT565M NN CT555W ...

Page 13: ...num heat sink because it is hot 1 Discharge high voltage charge 2 Remove the H V lead wire from magnetron terminals 3 Disconnect 2 connectors from CN701 CN702 on H V Inverter U 4 Remove 1 screw holding grounding plate to the base 5 Bend back 1 locking metal tab on the base 6 Remove 1 screw holding Inverter bracket on the bottom of the base 7 Slide 5 locking tabs of Inverter bracket at the bottom o...

Page 14: ...9 Remove 1 screw holding grounding plate to H V Inverter 10 Seperate H V Inverter from Inverter bracket by freeing 3 catch hooks on the Inverter bracket 15 NN CT585S NN CT565M NN CT555W ...

Page 15: ...oor Opened Primary Latch Switch 0Ω Close Ω Open Secondary Latch Switch 0Ω Close Ω Open Power Relay RY1 Ω Open Ω Open 5 2 Short Switch 1 Unplug lead wires from Inverter Power Supply U primary terminals 2 Connect test probes of ohm meter to the disconnected leads that were connected to Inverter Power Supply U 3 Test the continuity of short switch with door opened and closed positions using lowest sc...

Page 16: ...oven s AC power supply cord into outlet 4 Program DPC a Press Clock pad once b Press Delay Stand pad once c Press Start pad once d Press Micro Power pad once 5 Program oven at High power for 1 minute and press Start pad a After approximately 3 seconds oven stops operating b During oven operation the input current is approximately 0 4A INPUT CURRENT FAILURE CODE Unplug CN701 0 4A Oven stops in 3 se...

Page 17: ...again by following the component test procedures 6 2 Measurement of microwave output The output power of the magnetron can be determined by performing IEC standard test procedures However due to the complexity of IEC test procedures it is recommended to test the magnetron using the simple method outlined below Necessary Equipment 1 liter beaker Glass thermometer Wrist watch or stopwatch NOTE Check...

Page 18: ...trol panel Always touch ground while working on this panel to discharge any static charge in your body 7 230 240V AC is present on the digital programmer circuit Terminals of power relay s and primary circuit of Digital Programmer Circuit When troubleshooting be cautious of possible electrical shock hazard Before troubleshooting operate the microwave oven following the correct operating procedures...

Page 19: ... or loose connection of high voltage circuit especially magnetron filament circuit NOTE Large contact resistance will cause lower magnetron filament voltage and cause magnetron to have lower output and or be intermittent 3 Defective high voltage component H V Inverter Power Supply U Magnetron Check high voltage component according to component test procedure and replace if it is defective 4 Open o...

Page 20: ... you must program the DPC into TEST MODE press Clock pad once press Delay Stand pad once Press Start pad once press Micro Power pad once Program unit for operation H95 H97 H98 H99 appears in display window a short time after Start pad is pressed and there is no microwave oscillation Alternate way to troubleshoot oven with AC Ampere meter used H95 H97 H98 H99 appears in display window a short time ...

Page 21: ...edure 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 Z606YBH20GP 2 D702 is OK Replace magnetron Shut off in 3 seconds after Start 1 Less than ...

Page 22: ...02 ZCWF4305N851 FILM CAPACITOR 1 3µF 250VDC DB701 Z0FBBQ000006 RECTIFIER BRIDGE 1 L701 Z5020W100AP CHOKE COIL 1 R702 Z0CM562JA002 SAND BAR RESISTOR 1 5 6KΩ 15W T701 Z609ABA00GP TRANSFORMER 1 INCLUDING D701 D702 C706 C707 D701 D702 Z0FBAZ000006 DIODE 2 C706 Z0C3F562A002 FILM CAPACITOR 1 5600PF 3KV C707 Z0C3F822A002 FILM CAPACITOR 1 8200PF 3KV 23 NN CT585S NN CT565M NN CT555W ...

Reviews: