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R879(W)

6 – 2

2. The peak reverse voltage of D2 of the rectifier goes beyond the

rated peak reverse voltage 1.7 KV in the voltage doubler circuit.

3. D2 of the rectifier is shorted.

4. The large electric currents flow through the high voltage winding of

the high voltage transformer.

5. The large electric currents beyond 8A flow through the primary

winding of the high voltage transformer.

6. The fuse F2 F8A blows by the large electric currents.

7. The power supplying to the high voltage transformer is cut off.

The noise filter assembly prevents radio frequency interference that
might flow back in the power circuit.

The turntable motor rotates the turntable.

The fan motor drives a blade which draws external cool air. This cool
air is directed through the air vanes surrounding the magnetron and
cools the magnetron. This air is channelled through the oven cavity to
remove steam and vapours given off from heating food. It is then
exhausted through the exhausting air vents of the oven cavity.

The convection motor drives the convection fan and provide the
heated air.

The grill heating element is provided to brown the food and is located
on the top of the oven cavity.

The grill heating element is provided to brown the food and is located
at the base of the oven cavity.

°C, the fan motor remains rotat-

ing. Automatically the fan motor will be shut down at low temperature
(less than 105

°C).

Figure D-2. Convection Cooking System

The oven will stop its operation when there is a fire in the oven cavity
in microwave cooking condition. 

LSI measures the voltage across the temperature measurement circuit
intermittently within 32-seconds time base since the oven is started in
microwave cooking condition. The oven will stop its operation when
the difference of the voltage is more than 0.781 volts in microwave
cooking condition.

1. Within a 32-seconds base, the thermistor is energized for 2 sec-

onds. At that time, the voltage across the temperature measure-
ment circuit is measured.

2. The oven carries out the procedure above again. If the second volt-

age is 0.781V higher than first voltage, LSI judges it as a fire in the
oven cavity and stop the oven.

3. When LSI judges it as a fire in the oven cavity, LSI will switch off the

relays to high voltage transformer and fan motor and LSI stops
countering down.

1. If the temperature of the thermistor does not rise to more than 40

°C

after 4 minutes and 15 seconds from when the oven is started in
convection, grill (top and bottom grills) or dual cooking mode, the
oven is turned off.

2. When the thermistor or the wire harness to the thermistor is

opened, the oven is turned off after 4 minutes and 15 seconds
because this condition is same as above.

Door

Oven Cavity

Grill Heating
Element

Bottom Grill
Heating Element

Convection
Passage

Cooling
Fan

Convection
Motor

Convection
Fan

Turntable

Insulation

Turntable
Motor

THERMISTOR

SENSING

VOLTAGE

ON

OFF

ON

OFF

30

32 (sec.)

Sensing the voltage across temperature measurement circuit.

R879(W)

6 – 2

2. The peak reverse voltage of D2 of the rectifier goes beyond the

rated peak reverse voltage 1.7 KV in the voltage doubler circuit.

3. D2 of the rectifier is shorted.

4. The large electric currents flow through the high voltage winding of

the high voltage transformer.

5. The large electric currents beyond 8A flow through the primary

winding of the high voltage transformer.

6. The fuse F2 F8A blows by the large electric currents.

7. The power supplying to the high voltage transformer is cut off.

The noise filter assembly prevents radio frequency interference that
might flow back in the power circuit.

The turntable motor rotates the turntable.

The fan motor drives a blade which draws external cool air. This cool
air is directed through the air vanes surrounding the magnetron and
cools the magnetron. This air is channelled through the oven cavity to
remove steam and vapours given off from heating food. It is then
exhausted through the exhausting air vents of the oven cavity.

The convection motor drives the convection fan and provide the
heated air.

The grill heating element is provided to brown the food and is located
on the top of the oven cavity.

The grill heating element is provided to brown the food and is located
at the base of the oven cavity.

°C, the fan motor remains rotat-

ing. Automatically the fan motor will be shut down at low temperature
(less than 105

°C).

Figure D-2. Convection Cooking System

The oven will stop its operation when there is a fire in the oven cavity
in microwave cooking condition. 

LSI measures the voltage across the temperature measurement circuit
intermittently within 32-seconds time base since the oven is started in
microwave cooking condition. The oven will stop its operation when
the difference of the voltage is more than 0.781 volts in microwave
cooking condition.

1. Within a 32-seconds base, the thermistor is energized for 2 sec-

onds. At that time, the voltage across the temperature measure-
ment circuit is measured.

2. The oven carries out the procedure above again. If the second volt-

age is 0.781V higher than first voltage, LSI judges it as a fire in the
oven cavity and stop the oven.

3. When LSI judges it as a fire in the oven cavity, LSI will switch off the

relays to high voltage transformer and fan motor and LSI stops
countering down.

1. If the temperature of the thermistor does not rise to more than 40

°C

after 4 minutes and 15 seconds from when the oven is started in
convection, grill (top and bottom grills) or dual cooking mode, the
oven is turned off.

2. When the thermistor or the wire harness to the thermistor is

opened, the oven is turned off after 4 minutes and 15 seconds
because this condition is same as above.

Door

Oven Cavity

Grill Heating
Element

Bottom Grill
Heating Element

Convection
Passage

Cooling
Fan

Convection
Motor

Convection
Fan

Turntable

Insulation

Turntable
Motor

THERMISTOR

SENSING

VOLTAGE

ON

OFF

ON

OFF

30

32 (sec.)

Sensing the voltage across temperature measurement circuit.

R879(W)

6 – 2

2. The peak reverse voltage of D2 of the rectifier goes beyond the

rated peak reverse voltage 1.7 KV in the voltage doubler circuit.

3. D2 of the rectifier is shorted.

4. The large electric currents flow through the high voltage winding of

the high voltage transformer.

5. The large electric currents beyond 8A flow through the primary

winding of the high voltage transformer.

6. The fuse F2 F8A blows by the large electric currents.

7. The power supplying to the high voltage transformer is cut off.

The noise filter assembly prevents radio frequency interference that
might flow back in the power circuit.

The turntable motor rotates the turntable.

The fan motor drives a blade which draws external cool air. This cool
air is directed through the air vanes surrounding the magnetron and
cools the magnetron. This air is channelled through the oven cavity to
remove steam and vapours given off from heating food. It is then
exhausted through the exhausting air vents of the oven cavity.

The convection motor drives the convection fan and provide the
heated air.

The grill heating element is provided to brown the food and is located
on the top of the oven cavity.

The grill heating element is provided to brown the food and is located
at the base of the oven cavity.

°C, the fan motor remains rotat-

ing. Automatically the fan motor will be shut down at low temperature
(less than 105

°C).

Figure D-2. Convection Cooking System

The oven will stop its operation when there is a fire in the oven cavity
in microwave cooking condition. 

LSI measures the voltage across the temperature measurement circuit
intermittently within 32-seconds time base since the oven is started in
microwave cooking condition. The oven will stop its operation when
the difference of the voltage is more than 0.781 volts in microwave
cooking condition.

1. Within a 32-seconds base, the thermistor is energized for 2 sec-

onds. At that time, the voltage across the temperature measure-
ment circuit is measured.

2. The oven carries out the procedure above again. If the second volt-

age is 0.781V higher than first voltage, LSI judges it as a fire in the
oven cavity and stop the oven.

3. When LSI judges it as a fire in the oven cavity, LSI will switch off the

relays to high voltage transformer and fan motor and LSI stops
countering down.

1. If the temperature of the thermistor does not rise to more than 40

°C

after 4 minutes and 15 seconds from when the oven is started in
convection, grill (top and bottom grills) or dual cooking mode, the
oven is turned off.

2. When the thermistor or the wire harness to the thermistor is

opened, the oven is turned off after 4 minutes and 15 seconds
because this condition is same as above.

Door

Oven Cavity

Grill Heating
Element

Bottom Grill
Heating Element

Convection
Passage

Cooling
Fan

Convection
Motor

Convection
Fan

Turntable

Insulation

Turntable
Motor

THERMISTOR

SENSING

VOLTAGE

ON

OFF

ON

OFF

30

32 (sec.)

Sensing the voltage across temperature measurement circuit.

R879(W)

6 – 2

2. The peak reverse voltage of D2 of the rectifier goes beyond the

rated peak reverse voltage 1.7 KV in the voltage doubler circuit.

3. D2 of the rectifier is shorted.

4. The large electric currents flow through the high voltage winding of

the high voltage transformer.

5. The large electric currents beyond 8A flow through the primary

winding of the high voltage transformer.

6. The fuse F2 F8A blows by the large electric currents.

7. The power supplying to the high voltage transformer is cut off.

The noise filter assembly prevents radio frequency interference that
might flow back in the power circuit.

The turntable motor rotates the turntable.

The fan motor drives a blade which draws external cool air. This cool
air is directed through the air vanes surrounding the magnetron and
cools the magnetron. This air is channelled through the oven cavity to
remove steam and vapours given off from heating food. It is then
exhausted through the exhausting air vents of the oven cavity.

The convection motor drives the convection fan and provide the
heated air.

The grill heating element is provided to brown the food and is located
on the top of the oven cavity.

The grill heating element is provided to brown the food and is located
at the base of the oven cavity.

°C, the fan motor remains rotat-

ing. Automatically the fan motor will be shut down at low temperature
(less than 105

°C).

Figure D-2. Convection Cooking System

The oven will stop its operation when there is a fire in the oven cavity
in microwave cooking condition. 

LSI measures the voltage across the temperature measurement circuit
intermittently within 32-seconds time base since the oven is started in
microwave cooking condition. The oven will stop its operation when
the difference of the voltage is more than 0.781 volts in microwave
cooking condition.

1. Within a 32-seconds base, the thermistor is energized for 2 sec-

onds. At that time, the voltage across the temperature measure-
ment circuit is measured.

2. The oven carries out the procedure above again. If the second volt-

age is 0.781V higher than first voltage, LSI judges it as a fire in the
oven cavity and stop the oven.

3. When LSI judges it as a fire in the oven cavity, LSI will switch off the

relays to high voltage transformer and fan motor and LSI stops
countering down.

1. If the temperature of the thermistor does not rise to more than 40

°C

after 4 minutes and 15 seconds from when the oven is started in
convection, grill (top and bottom grills) or dual cooking mode, the
oven is turned off.

2. When the thermistor or the wire harness to the thermistor is

opened, the oven is turned off after 4 minutes and 15 seconds
because this condition is same as above.

Door

Oven Cavity

Grill Heating
Element

Bottom Grill
Heating Element

Convection
Passage

Cooling
Fan

Convection
Motor

Convection
Fan

Turntable

Insulation

Turntable
Motor

THERMISTOR

SENSING

VOLTAGE

ON

OFF

ON

OFF

30

32 (sec.)

Sensing the voltage across temperature measurement circuit.