R-7H55
17
TEST PROCEDURES (CONT'D)
PROCEDURE
LETTER
COMPONENT TEST
2-3 Other possible problems caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
M
KEY UNIT TEST
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon is marking
good contact, verify that the door sensing switch(stop switch) operates properly; that is the contacts are
closed when the door is closed andopen when the door is open. If the door sensing switch(stop switch)
is good, disconnecct 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 jamper wire between the pins
that correspond to the STOP/CLEAR pad marking 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 a 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.
KEY UNIT
G-1
G-2
G-3
G-4
G-5
G-6
G-7
G-8
G-9
G-10
G-11
G-12
5
SLOW
COOK
GRILL
MICRO
WAVE
LEVEL
EASY
DEFROST
AUTO
COOK
MORE
LESS
STOP
CLEAR
INSTANT
COOK
START
LOW
MIX
HIGH
MIX
SENSOR
REHEAT
CONVEC
160˚C
4
150˚C
3
130˚C
2
70˚C
1
40˚C
0
250˚C
9
230˚C
8
220˚C
7
200˚C
6
180˚C
AUTO
START
CLOCK
STEAM
MENU
RICE
COOK
CARRY OUT 4R CHECKS
N
RELAY TEST
CARRY OUT 3D CHECKS
Remove the outer case and check voltage between Pin Nos. 1 and 3 of the 9 pin connector (A) on the
control unit with an A.C. voltmeter.
The meter should indicat 220 volts, if not check oven circuit.
Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation,
convection cooking operation or grill 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.
CARRY OUT 4R CHECKS
RELAY SYMBOL
OPERATIONAL
VOLTAGE
CONNECTED COMPONENTS
RY1
Approx. 26.0V.D.C.
Oven lamp/Turntable motor
RY2
Approx. 25.5V.D.C.
High voltage transformer
RY3
Approx. 25.0V.D.C.
Convection heating element
RY4
Approx. 26.0V.D.C.
Fan motor
RY5
Approx. 26.0V.D.C.
Convection motor
RY6
Approx. 26.0V.D.C.
Damper motor