R-7N76(W)M
R-7N76(B)M
18
TEST PROCEDURES (CONT'D)
CARRY OUT 4R CHECKS
STEPS
OCCURANCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present at
POWER terminal of CPU connector (CN-A)
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 repair.
3
Only pattern at "a" is broken.
*Insert jumper wire J1 and solder. (CARRY OUT 3D
CHECKS BEFORE REPAIR)
4
Pattern at "a" and "b" are broken.
*Insert the coil RCILF2003YAZZ between "c" and "d".
(CARRY OUT 3D CHECKS BEFORE REPAIR)
To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary
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.
Q
PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD(PWB) IS OPEN
CARRY OUT 3D CHECKS.
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 defective
parts.
CARRY OUT 4R CHECKS.
RELAY SYMBOL
OPERATIONAL
VOLTAGE
CONNECTED COMPONENTS
RY1
Approx. 25.0V.D.C.
Oven lamp / Turntable motor
RY2
Approx. 25.0V.D.C.
High voltage transformer
RY3
Approx. 25.0V.D.C.
Convection heater
RY4
Approx. 25.0V.D.C.
Grill heater
RY5
Approx. 25.5V.D.C.
Convection motor
RY6
Approx. 25.5V.D.C.
Fan motor
RY7
Approx. 25.5V.D.C.
Damper motor
P
RELAY TEST
COMPONENT TEST
PROCEDURE
LETTER
1. CARRY OUT 3D CHECKS.
2. Disconnect the leads from the primary of the high voltage transformer. Make sure that the leads remain
isolated from other oven components and chassis. (Use insulation tape if necessary.)
3. Close the door.
4. Reconnect the supply.
5. Check the voltage between Pin Nos. 1 and 3 of the 6 pin connector (H) on the control unit with an A.C.
voltmeter. The meter should indicate 240 volts, if not check oven circuit.
6. RY1, RY2 , RY3, RY4, RY5, RY6 and RY7 TEST
These 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.
5
3
1
a
S1
P
VRS1
POWER
D1
CONV M
F
(J1)
RY5
b
c
d
