Sharp MMD24B ユーザーズマニュアル

3

Microwave Oven units contain circuitry capable of producing very high voltage and current, 
contact with following parts  may result in a severe, possibly fatal, electrical shock.

(Example)

High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectifier 
Assembly,  High Voltage Harness, Heating Elements, etc..

Read the Service Manual carefully and follow all instructions.

.  Disconnect the power supply cord  

,   a n d   t h e n 

remove cabinet.

2.  Open the drawer and keep it open.
3.  Discharge high voltage capacitor.

The  high-voltage  capacitor  remains  charged  about  60 
seconds  after  the  oven  has  been  switched  off. Wait  for 
60 seconds and then short-circuit the connection of the 
high-voltage capacitor (that is the connecting lead of the 
high-voltage rectifier) against the chassis with the use of 
an insulated screwdriver. 

Whenever  troubleshooting  is  performed  the  power  supply  
must be disconnected. It may, in  some cases, be necessary 
to connect the power supply after the outer case has been 
removed, in this event:
.  Disconnect  the  power  supply  cord,  and  then  remove 

neccessary covers.

2.  Open the drawer and keep it open.
3.  Discharge high voltage capacitor.
4.  Disconnect  the  leads  to  the  primary  of  the  power 

transformer.

5.  Ensure  that  the  leads  remain  isolated  from  other 

components and oven chassis by using insulation tape.

6.  After that procedure, reconnect the power supply cord.

When the testing is completed,
.  Disconnect  the  power  supply  cord,  and  then  remove 

covers.

2.  Open the drawer and keep it open.
3.  Discharge high voltage capacitor.
4.  Reconnect  the  leads  to  the  primary  of  the  power 

transformer.

5.  Reinstall the covers.
6.  Reconnect the power supply cord.
7.  Run the unit and check all functions.

.  Reconnect all leads removed from components during 

testing.

2.  Reinstall the covers.
3.  Reconnect the power supply cord.
4.  Run the oven and check all functions.

Microwave ovens should not be operated empty. To test for 
the presence of microwave energy within a cavity, place a 
cup of cold water on the oven tray, close the drawer and set  
the power to HIGH and set the microwave timer for two (2) 
minutes. When the two minutes has elapsed (timer at zero) 
carefully check that the water is now hot. If the water remains 
cold carry out Before Servicing procedure and re-examine 
the connections to the component being tested. 

When all service work is completed and the oven is fully 
assembled, the microwave power output should be checked 
and a microwave leakage test should be  carried out.