Service manual

R-890SLM
a
7
0
P
J
1
S
A-NC
[15] O: RELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 5 and 7 of the 4 pin connector (E) on the control unit with an A.C.
voltmeter. The meter should indicate 230-240 volts, if not check oven circuit.
Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill operation, convection operation or
combi 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. 18.0V D.C. Oven lamp / Turntable motor
RY
2 APPROX. 18.0V D.C. High voltage transformer
RY
3 APPROX. 24.0V D.C. Grill (Top) heating element
RY
4 APPROX. 24.0V D.C. Bottom heating element
RY
5 APPROX. 24.0V D.C. Touch control transformer
RY
6 APPROX. 24.0V D.C. Fan motor
RY
7 APPROX. 24.0V D.C. Convection motor
CARRY OUT
4R CHECKS.
[16] P: PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD
(PWB) IS OPEN
To protect the electronic circuits, this model is provided with a fine foil pattern added to the input circuit on the PWB, this foil pattern
acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given below for repair.
Problem: POWER ON, indicator does not light up.
CARRY OUT
3D CHECKS.
STEPS OCCURRENCE CAUSE OR CORRECTION
1
The rated AC voltage is not present between Pin Nos.
5 and 7 of the 4-pin connector (E).
Check supply voltage and oven power cord.
2
The rated AC voltage is present at primary side of low
voltage transformer.
Low voltage transformer or secondary circuit defective.
Check and replace the touch control transformer or the
control unit.
3 Pattern at “a” is broken.
Replace the control unit.
(CARRY OUT
3D CHECKS BEFORE REPAIR)
NOTE: *At the time of these repairs, make a visual inspection of the varistor for burning
damage and examine the transformer with tester for the presence of layer short
circuit (check primary coil resistance).
If any abnormal condition is detected, replace the control unit.
CARRY OUT
4R CHECKS.
8 - 5
WH3-7
WH3-8
WH3-10
WH3-9
4-
3H
W
3
-
3
HW
2-
3
H
W
1
-
3HW
S
SE
RPXE
K
O
O
C
SW1
/
P
OT
S
RAEL
C
SW13
KITCHEN TIME
R
/ CLOCK SET
SW14
L
L
IR
G
SW6
IB
N
O
C
SW4
T
RATS
SW15
OFN
I
SW10
ETUNIM OTUA
SW12
KOOC OTUA
SW11
SHORT CUTS
SW9
SY
A
E&
K
C
I
U
Q
SW8
)
(
.V ?NOC
SW7
RETNE
SW3
REWO
P
O
R
C
IM
SW5
SS
E
RPXE
TSOR
F
ED
SW2
CARRY OUT 4R CHECKS.
Service_R-890SLM.indd 19 4/25/09 10:55:24 AM