R-8000G
22
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
1. Tact switches on the CPU unit or the control unit (switch unit)
1) Re-install the outer case (cabinet).
2) Reconnect the power supply cord after the outer case is installed.
3) Run the oven and check all functions.
The following symptoms indicate a defective tact switch.
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.
If the tact switch is defective.
1) Disconnect the power supply cord.
2) Remove the outer case cabinet, referring to "OUTER CASE CABINET REMOVAL".
3) Open the door and block it open.
4) Discharge high voltage capacitor.
5) Check which tact switch is defective, one on the CPU unit or one on the control unit (switch unit),
referring to "TACT SWITCH TEST". (Procedure U)
6) Replace the unit that has a defective tact switch.
7) Reconnect all leads removed from components during testing.
8) Re-install the outer case (cabinet).
9) Reconnect the power supply cord after the outer case is installed.
10)Run the oven and check all functions.
2. CPU Unit
The following symptoms indicate a defective CPU unit. Reconnect the power supply cord. And check for
followings.
2-1 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.
2-2 Other possible problems caused by defective CPU unit.
a) Cooking is not possible.
3. Other possible problems caused by defective control unit (switch unit).
a) Buzzer does not sound or continues to sound.
4. Other possible problems caused by defective power unit.
a) Cooking is not possible.
b) Electrical parts do not operate.
c) Oven or electrical parts do not stop.
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.
U
TACT SWITCH TEST
1. Disconnect the power supply cord.
2. Remove the outer case cabinet, referring to "OUTER CASE CABINET REMOVAL".
3. Open the door and block it open.
4. Discharge high voltage capacitor.
5. Remove the CPU unit and the control unit (switch unit), referring to "CONTROL PANEL ASSEMBLY, CPU
UNIT AND CONTROL UNIT REMOVAL".
6. By using an ohmmeter, check the tact switch operation.
7. When the tact switch is not depressed, an ohmmeter should indicate an open circuit. When the tact switch
is depressed, an ohmmeter should indicate a short circuit. If improper operation is indicated, the tact switch
is probably defective.
8. Refer to the switch unit matrix, and judge which unit has any defective tact switches.
