K: Key Unit Test; L: Relay Test - Sharp R-530EK-T Service Manual

R530EWT
g) The figure of all digits flicker.
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.
3. If the Key unit or the Control unit is defective.
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) Replace the Control unit assembly.
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.
4. 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.

[11] K: KEY UNIT TEST

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. If the display fails to clear when the STOP/CLEAR
pad is depressed, first verify the flat ribbon cable is
making good contact, verify that the door sensing
switch (stop switch) operates properly; that is the con-
tacts are closed when the door is closed and open
when the door is open. If the door sensing switch
(stop switch) is good, disconnect 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 jumper wire between the pins that correspond to the STOP/CLEAR
pad making 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 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.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.

[12] L: RELAY TEST

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. Disconnect the leads to the primary of the power transformer.
5. Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.
6. After that procedure, re-connect the power supply cord.
G 1 G 2 G 3 G 4
Beverage
1
Center
Fresh
From the
6
Rice
vegetables
Pantry
Start
Ground
Poultry
meat
Touch On
Fish
Entrees Vegetables
Breakfast
Seafood
Defrost
Center
8 – 5
G 5 G 6 G 7 G 8
2 3 4 5
7 8 9 0
Keep
Timer
Minute
Snacks
Warm
Clock Plus
Plus
15
Stop
Power
Minute
Lunch
Level
Clear
Recipes
Custom Baked Sensor
Popcorn
Help potatoes reheat
G 9
G10
G11
G12
G13
G14