Sharp MMD24B 사용자 설명서

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2
MMD24S
MMD24B
 
RELAY TEST
4)  Reconnect all leads removed from components during testing.
5)  Re-install the covers.
6)  Reconnect the power supply cord after the covers are installed.
7)  Run the oven and check all functions.
TEST PROCEDURES
 
PROCEDURE 
 
LETTER 
COMPONENT TEST
   
 
KEY UNIT TEST
                              . Disconnect the power supply cord, and then remove outer case.
.  Disconnect the power supply cord, and then remove outer case.
2.  Open the door and block it open.
3.  Discharge high voltage capacitor.
4.  Disconnect the leads to the primary of the power transformer.
5.  Ensure that these leads remain isolated from other components and oven chassis by using insulation 
tape. 
6.  After that procedure, re-connect the power supply cord.
7.  Remove the outer case and check voltage between Pin Nos. 5 and 7 of the 4 pin connector (CN-A) 
on the power unit with an A.C. voltmeter.
 
The meter should indicate 20 volts, if not check oven circuit.
     RY, RY2, RY3 and RY4 Relay Test 
 
These relays are operated by D.C. voltage 
 
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
DC. voltage indicated 
Defective relay.
DC. voltage not indicated 
Check diode which is connected to the relay coil. If diode is good, 
control unit is defective.
 
RELAY SYMBOL 
OPERATIONAL VOLTAGE 
CONNECTED COMPONENTS
 
RY 
Approx. 26V D.C. 
Oven lamp / Common
 
RY2 
Approx. 25V D.C. 
Power transformer
 
RY3 
Approx. 26V D.C. 
Stirrer motor
 
RY4 
Approx. 26V D.C. 
Fan motor
 
RY5 
Approx. 26V D.C. 
Switching regurator for drawer motor
  8. Disconnect the power supply cord, and then remove outer case.
  9. Open the door and block it open.
0. Discharge high voltage capacitor.
2. Open the drawer and block it open.
3. Discharge high voltage capacitor. 
4. If the display fails to clear when the STOP/CLEAR pad is depressed, 
first verify the flat ribbon cable is making good contact, verify that 
the door sensing switch (stop switch) operates properly; that is the 
contacts are closed when the drawer is closed and open when the 
drawer  is  open.  If  the  door  sensing  switch  (stop  switch)  is  good, 
disconnect  the  flat  ribbon  cable  that  connects  the  key  unit  to  the 
control  unit  and  make  sure  the  drawer  sensing  switch  is  closed 
(either close the  drawer or short the door sensing switch connecter). 
Use  the  Key  unit  matrix  indicated  on  the  control  panel  schematic 
and place a jumper wire between the pins that correspond to the 
STOP/CLEAR  pad  making  momentary  contact.  If  the  control  unit 
responds by clearing with a beep the key unit is faulty and must be 
replaced. If the control unit does not respond, it is faulty and must be 
replaced. If a specific pad does not respond, the above method may 
be used (after clearing the control unit) to determine if the control 
unit or key pad is at fault.
5. Reconnect all leads removed from components during testing.
6. Re-install the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
STOP/
CLEAR
REHEAT
6
START/
EASY
MINUTE
1
2
7
SENSOR
COOK
SENSOR
REHEAT
DEFROST
9
8
3
4
OPEN
SENSOR
POPCORN
MICRO
WARM
TIMER
CLOCK
CLOSE
0
5
POWER
LEVEL
SET UP/
        HELP
CONTROL
LOCK
ON/OFF