Tech Sheet

11
À L’USAGE DU TECHNICIEN DE MAINTENANCE
UNIQUEMENT
Composants Test/résultats
HT Transformateur REMARQUE: Le l supérieur est orange. Le l inférieur est blanc.
1. Débrancher le four à micro-ondes ou déconnecter la source de courant électrique.
2. Déconnecter les conducteurs.
3. Mesurer la résistance:
■ Bobinage primaire: 0,2 à 0,4 ohm (environ)
■ Bobinage secondaire: 60 à 90 ohms (environ)
■ Bobinage du lament: Moins de 1 ohm
■ Bobinage primaire vers la terre: Normale : Innie
■ Bobinage du lament vers la terre: Normale : Innie
Magnétron
1. Débrancher le four à micro-ondes ou déconnecter la source de courant électrique.
2. Déconnecter les conducteurs. Vérier que le joint est en bon état.
3. Mesurer la résistance:
■ Broche du lament: Normale : Moins de 1 ohm
■ Filament vers châssis: Normale : Innie
HT Condensateur
1. Débrancher le four à micro-ondes ou déconnecter la source de courant électrique.
2. Déconnecter les conducteurs.
3. Préparer un circuit comportant les ls conducteurs, une pile de 9 VCC et une résistance de 10 K-ohms.
4. Connecter la pile de 9 VCC au condensateur haute tension.
5. Mesurer la résistance:
■ Broche à broche: Normale : 9 V (environ); anormal: 0 V (environ)
■ Broche vers boîtier: Normale : 0 V (environ); anormal: 0 V (environ)
HT Diode REMARQUE: Certains ohmmètres peu coûteux ne comportent pas une pile de 9 volts; dans ce cas on
peut obtenir une valeur de résistance innie lors du test de la diode, dans chaque direction. Pour mesurer
correctement la résistance de la diode haute tension, il est préférable d'utiliser un ohmmètre qui comporte
une pile de 9 V (échelle 10X).
1. Débrancher le four à micro-ondes ou déconnecter la source de courant électrique.
2. Dans le cas de l'emploi d'un ohmmètre qui ne comporte pas une pile de 9 volts, préparer un circuit
comportant en série les conducteurs de branchement, une pile de 9 VCC et une résistance de 10
K-ohms.
3. Connecter la pile de 9 VCC à la diode haute tension.
4. Mesurer la résistance:
■ Vers l’avant: Normale : 5 à 6 V (environ); anormal: ouverte—9 V (environ); courte—0 V (environ)
■ Inversée Normale : 9 V (environ); anormal: ouverte—9 V (environ); courte—0 V (environ)
Moteur - hélice de répartition
1. Débrancher le four à micro-ondes ou déconnecter la source de courant électrique.
2. Déconnecter les conducteurs.
3. Mesurer la résistance:
■ Normale : 3,8k ± 0,2k ohms (environ)
■ Anormal: Innie
Moteur du ventilateur de
refroidissement
1. Débrancher le four à micro-ondes ou déconnecter la source de courant électrique.
2. Déconnecter les conducteurs.
3. Mesurer la résistance:
■ Normale :
A 95 à 120 ohms (environ)
B 10 à 25 ohms (environ)
■ Anormal: Innie
5
Microwave Oven Power Output Test
1. Place 8 oz (250 mL) of lukewarm water in the center of the
microwave oven.
2. Operate on HIGH power level for 2 minutes. Water should be
hot.
NOTE: If the water takes longer than 2 minutes to heat, this
may indicate either the operating voltage is lower than
110 volts or there is a problem with the microwave oven.
Component Tests
IMPORTANT:
■ Unplug microwave oven or disconnect power.
■ Discharge the high-voltage capacitor and remove the lead
wires from the primary winding of the high-voltage
transformer before conducting any of the following tests.
■ Remove the lead wires from the related component before
conducting any of the following tests.
■ Conduct a microwave energy test after performing any tests
or repairs to the microwave oven.
■ Check that all wire leads are in the correct positions before
operating the microwave oven.
■ All operational checks using microwave energy must be done
with the microwave oven loaded with a minimum of 8 oz
(250 mL) of water in a microwave safe container.
■ Grasp wire connectors when removing the wire leads from
microwave oven parts.
■ All testing must be done with an ohmmeter having a
sensitivity of 20,000 ohms per volt DC or greater, and
powered by at least a 9-volt battery.
Components Test/Results
H.V. Transformer
NOTE: The inside lead wire is red. The outside lead wire is white. Do not reverse leads.
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Primary winding: 0.2 to 0.4 ohm (approximate)
■ Secondary winding: 60 to 90 ohms (approximate)
■ Filament winding: Less than 1 ohm
■ Primary winding to grounding: Normal: Infinite
■ Filament winding to grounding: Normal: Infinite
Magnetron
1. Unplug microwave oven or disconnect power.
2. Remove wire leads. Check that the seal is in good condition.
3. Measure resistance:
■ Filament terminal: Normal: Less than 1 ohm
■ Filament to chassis: Normal: Infinite
5
Microwave Oven Power Output Test
1. Place 8 oz (250 mL) of lukewarm water in the center of the
microwave oven.
2. Operate on HIGH power level for 2 minutes. Water should be
hot.
NOTE: If the water takes longer than 2 minutes to heat, this
may indicate either the operating voltage is lower than
110 volts or there is a problem with the microwave oven.
Component Tests
IMPORTANT:
■ Unplug microwave oven or disconnect power.
■ Discharge the high-voltage capacitor and remove the lead
wires from the primary winding of the high-voltage
transformer before conducting any of the following tests.
■ Remove the lead wires from the related component before
conducting any of the following tests.
■ Conduct a microwave energy test after performing any tests
or repairs to the microwave oven.
■ Check that all wire leads are in the correct positions before
operating the microwave oven.
■ All operational checks using microwave energy must be done
with the microwave oven loaded with a minimum of 8 oz
(250 mL) of water in a microwave safe container.
■ Grasp wire connectors when removing the wire leads from
microwave oven parts.
■ All testing must be done with an ohmmeter having a
sensitivity of 20,000 ohms per volt DC or greater, and
powered by at least a 9-volt battery.
Components Test/Results
H.V. Transformer
NOTE: The inside lead wire is red. The outside lead wire is white. Do not reverse leads.
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Primary winding: 0.2 to 0.4 ohm (approximate)
■ Secondary winding: 60 to 90 ohms (approximate)
■ Filament winding: Less than 1 ohm
■ Primary winding to grounding: Normal: Infinite
■ Filament winding to grounding: Normal: Infinite
Magnetron
1. Unplug microwave oven or disconnect power.
2. Remove wire leads. Check that the seal is in good condition.
3. Measure resistance:
■ Filament terminal: Normal: Less than 1 ohm
■ Filament to chassis: Normal: Infinite
6
H.V. Capacitor
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Prepare the DC 9-volt battery and 10k ohms resistance including wire leads.
4. Connect the DC 9-volt battery to the H.V. capacitor.
5. Measure resistance:
■ Terminal to terminal: Normal: 9 volts (approximate); Abnormal: 0 volts (approximate)
■ Terminal to case: Normal: 0 volts (approximate); Abnormal: 0 volts (approximate)
H.V. Diode
NOTE: Some inexpensive ohmmeters do not have a 9-volt battery incorporated in them, and may
indicate infinite resistance in both directions when testing the diode. It is recommended that you use an
ohmmeter with a 9-volt battery on the 10x scale to properly test the H.V. diode.
1. Unplug microwave oven or disconnect power.
2. For ohmmeters without a 9-volt battery, prepare the DC 9-volt battery and 10k ohms resistor in
series including wire leads.
3. Connect the DC 9-volt battery to the H.V. diode.
4. Measure continuity:
■ Forward: Normal: 5 to 6 volts (approximate); Abnormal: Open—9 volts (approximate); Short—0
volts (approximate)
■ Reverse: Normal: 9 volts (approximate); Abnormal: Open—9 volts (approximate); Short—0 volts
(approximate)
Stirrer Motor
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Normal: 3.8k ± 0.2k ohms (approximate)
■ Abnormal: Infinite
Cooling Fan Motor
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Normal:
A 95 to 120 ohms (approximate)
B 10 to 25 ohms (approximate
■ Abnormal: Infinite
AC Line Filter
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Normal: L(1) to L(2) (coil): Less than 1 ohm;
N(1) to N(2) (coil): Less than 1 ohm
■ Abnormal: Infinite
■ Normal: L(1) or L(2) to N(1) or N(2) (resistor): 1.5M ohms
■ Abnormal: 0 ohms
Components Test/Results
6
H.V. Capacitor
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Prepare the DC 9-volt battery and 10k ohms resistance including wire leads.
4. Connect the DC 9-volt battery to the H.V. capacitor.
5. Measure resistance:
■ Terminal to terminal: Normal: 9 volts (approximate); Abnormal: 0 volts (approximate)
■ Terminal to case: Normal: 0 volts (approximate); Abnormal: 0 volts (approximate)
H.V. Diode
NOTE: Some inexpensive ohmmeters do not have a 9-volt battery incorporated in them, and may
indicate infinite resistance in both directions when testing the diode. It is recommended that you use an
ohmmeter with a 9-volt battery on the 10x scale to properly test the H.V. diode.
1. Unplug microwave oven or disconnect power.
2. For ohmmeters without a 9-volt battery, prepare the DC 9-volt battery and 10k ohms resistor in
series including wire leads.
3. Connect the DC 9-volt battery to the H.V. diode.
4. Measure continuity:
■ Forward: Normal: 5 to 6 volts (approximate); Abnormal: Open—9 volts (approximate); Short—0
volts (approximate)
■ Reverse: Normal: 9 volts (approximate); Abnormal: Open—9 volts (approximate); Short—0 volts
(approximate)
Stirrer Motor
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Normal: 3.8k ± 0.2k ohms (approximate)
■ Abnormal: Infinite
Cooling Fan Motor
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Normal:
A 95 to 120 ohms (approximate)
B 10 to 25 ohms (approximate
■ Abnormal: Infinite
AC Line Filter
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Normal: L(1) to L(2) (coil): Less than 1 ohm;
N(1) to N(2) (coil): Less than 1 ohm
■ Abnormal: Infinite
■ Normal: L(1) or L(2) to N(1) or N(2) (resistor): 1.5M ohms
■ Abnormal: 0 ohms
Components Test/Results
6
H.V. Capacitor
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Prepare the DC 9-volt battery and 10k ohms resistance including wire leads.
4. Connect the DC 9-volt battery to the H.V. capacitor.
5. Measure resistance:
■ Terminal to terminal: Normal: 9 volts (approximate); Abnormal: 0 volts (approximate)
■ Terminal to case: Normal: 0 volts (approximate); Abnormal: 0 volts (approximate)
H.V. Diode
NOTE: Some inexpensive ohmmeters do not have a 9-volt battery incorporated in them, and may
indicate infinite resistance in both directions when testing the diode. It is recommended that you use an
ohmmeter with a 9-volt battery on the 10x scale to properly test the H.V. diode.
1. Unplug microwave oven or disconnect power.
2. For ohmmeters without a 9-volt battery, prepare the DC 9-volt battery and 10k ohms resistor in
series including wire leads.
3. Connect the DC 9-volt battery to the H.V. diode.
4. Measure continuity:
■ Forward: Normal: 5 to 6 volts (approximate); Abnormal: Open—9 volts (approximate); Short—0
volts (approximate)
■ Reverse: Normal: 9 volts (approximate); Abnormal: Open—9 volts (approximate); Short—0 volts
(approximate)
Stirrer Motor
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Normal: 3.8k ± 0.2k ohms (approximate)
■ Abnormal: Infinite
Cooling Fan Motor
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Normal:
A 95 to 120 ohms (approximate)
B 10 to 25 ohms (approximate
■ Abnormal: Infinite
AC Line Filter
1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance:
■ Normal: L(1) to L(2) (coil): Less than 1 ohm;
N(1) to N(2) (coil): Less than 1 ohm
■ Abnormal: Infinite
■ Normal: L(1) or L(2) to N(1) or N(2) (resistor): 1.5M ohms
■ Abnormal: 0 ohms
Components Test/Results