5
R-209BW
J
KEY UNIT TEST
1. Disconnect the power supply cord and then remove outer case.
2. Open the door 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 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.
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
1. Disconnect the power supply cord and then remove outer case.
2. Open the door and blocked 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 No. 3 of the 2 pin connector (A) and the
common terminal of the relay RY2 on the control unit with an A.C. voltmeter.
The meter should indicate 120 volts, if not check oven circuit.
RY1 and RY2 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. 14.6V D.C.
Oven lamp / Turntable motor / Cooling fan motor
RY2
Approx. 13.0V D.C.
Power transformer
8. If any abnomal condition is detected, replace the control unit.
9. Disconnect the power supply cord and then remove outer case.
10. Open the door and block it open.
K
RELAY TEST
1
2
3
4
5
6
7
8
9
0
POWER
LEVEL
DINNER
PLATE
MINUTE
PLUS
BAKED
POTATO
EXPRESS
DEFROST
POPCORN
START
BEVERAGE
FRESH
VEGETABLES
ROLL,
MUFFIN
TIMER
CLOCK
G 6
G 5
G 4
G 3
G 2
G 1
G 7
G 8
G 9
G10
STOP
CLEAR
