18
R-55TS
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
3) Run the oven and check all functions.
The following symptoms indicate a defective switch unit.
a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.
d) When rotating the encoder (rotary dial), the cooking time can not be entered.
If the switch unit is defective, replace the switch unit together with the power unit.
2. Power Unit.
The following symptoms indicate a defective power unit. If the power unit is defective, replace the
power unit together with the switch unit.
2-1 In connection with pads.
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.
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.
d) Proper temperature measurement is not obtained.
When testing is completed,
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) Reconnect all leads removed from components during testing.
5) Re-install the outer case (cabinet).
6) Reconnect the power supply cord after the outer case is installed.
7) Run the oven and check all functions.
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.
Using an ohmmeter and referring to the switch unit matrix indicated on the control unit circuit, check the
circuit between the pins of the switch unit that correspond to the STOP/CLEAR pad. When the pad is
pressed, the ohmmeter should indicate short circuit. When the pad is released, the ohmmeter should
indicate open circuit. If incorrect readings are obtained, the key unit is faulty and must be replaced. About
the other pads, the above method may be used.
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.
M
SWITCH UNIT TEST
4.7K
A B C
R50
R51
R52
R53
4.7K
100K
100K
4
3
2
1
11
10
9
5
6
WH-B
13P HARNESS
12
7
8
Switch Unit
BAKE
MICRO
SW1
ENCODER
TOAST
SW13
BAKE
SW9
REHEAT
SW5
START/
MINUTEPLUS
SW1
SW2
STOP/
CLEAR
TIMER/
CLOCK
SW6
SW10
SNACKS
SW14
SW15
POP-
CORN
SW7
FROZEN
ENTREE
SW8
GRILL
SW11
EXPRESS
DEFROST
SW3
BEVERAGE
SW12
FRESH
VEGETABLES
SW4