9.2. NE-1037
CAUTION
1. Check grounding before checking for trouble.
2. Be careful of the high voltage circuit.
3. Discharge high voltage capacitor.
4. When checking the continuity of the switches or the high voltage transformer, disconnect one lead wire from these parts and then check
continuity with the AC plug removed. To do otherwise may result in a false reading or damage to your meter.
When disconnecting a plastic connector from a terminal, you must hold the plastic connector instead of the lead wire and then disconnect it,
otherwise lead wire may be damaged or the connector cannot by removed.
5. Do not touch any parts of the circuitry on the digital programmer circuit, since static electric discharge may damage this control panel.
Always touch yourself to ground while working on this panel to discharge any static charge in your body.
6. 230/240V AC is present at the shaded area
of the digital programmer circuit (Terminals of power relay´s and primary circuit of low voltage
transformer). When troubleshooting, be cautious of possible electrical shock hazard.
First of all operate the microwave oven following the correct operating procedures in order to find the exact cause of any trouble.
9.2.1. [TROUBLE 1] Oven does not start cooking
SYMPTOM
CAUSE
CORRECTIONS
1. Oven is dead.
1. Open or loose lead wire harness
Fuses is OK.
2. Open thermal cutout (Magnetron)
Check fan motor if thermal cutout is defective.
No display and no operation at all. 3. Open low voltage transformer
4. Defective DPC
2. Oven does not accept key input
(Program)
1. Key input is not in-sequence
Refer to operation procedure.
2. Open or loose connection of membrane key pad
to DPC (Flat cable)
3. Shorted or open membrane key board
4. Defective DPC
Refer to DPC troubleshooting.
3. Oven lamp and fan motor turn on
when oven is plugged in with door
closed.
1. Misalignment or loose wiring of secondary latch
switch
Adjust door and latch switches.
2. Defective secondary latch switch
4. Timer starts count down but no
microwave oscillation.
1. Off-alignment of latch switches
Adjust door and latch switches.
2. Defective primary latch switch
3. Open or loose wiring of power relay (RY1)
4. Defective power relay (RY1)
5. Defective DPC.
6. Open or loose connection of high voltage
circuit especially magnetron filament circuit
NOTE: Large contact resistance will bring lower
magnetron filament voltage and causing
magnetron to lower output and/or intermittent
oscillation.
7. Defective high voltage component
H.V. Transformer
H.V. Capacitor
H.V. Diode
Magnetron
Check
high
voltage
component
according
to
component test procedure and replace if it is defective.
22
NE-1027 / NE-1037
