Sharp R-25JT-F User Manual

R-25JT-F
19
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
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 door is closed and open when the door 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 door sensing switch is closed (either close the door 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.
N KEY UNIT TEST
1
11131519
12141620
17
18
3
4
5
6
7
8
9
0
G 8
G 7G 6G 5G 4
G 3
G 2
G 1
G 9
G 10
G 11
G 12
2
DOUBLE
QUANTITY
EXPRESS
DEFROST
SELECTA
TIME
SELECTA
POWER
STOP /
CLEAR
START SET
CHECK
SIGNAL
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
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 Pins No. 5 (or No. 3 at 230V) and No. 7 of the 7 pin
connector (A) on the control unit with an A.C. voltmeter.
The meter should indicate rated voltage, if not check oven circuit.
RY1, RY2 and RY3 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
RY1 Approx. 12.0V D.C. Oven lamp / Blower motor / Stirrer motors
RY2 Approx. 12.0V D.C. Power transformer 1
RY3 Approx. 12.0V D.C. Power transformer 2
8. Disconnect the power supply cord, and then remove outer case.
9. Open the door and block it open.
10. Discharge two high voltage capacitors.
11. Reconnect all leads removed from components during testing.
12. Re-install the outer case (cabinet).
O RELAY TEST
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST

Sharp R-25JT-F Specifications

General

Brand	Sharp
Model	R-25JT-F
Category	Microwave Oven
Language	English