Sharp R-330H, Руководство по обслуживанию

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R-330H
12
M RELAY TEST
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
L KEY UNIT TEST
1, CARRY OUT 3D CHECKS.
2. Isolate the key unit with the control panel frame to be tested.
3. Using an ohmmeter and referring to the key unit matrix indicated on the control unit circuit, check
the circuit between the pins of the key 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.
4. CARRY OUT 4R CHECKS.
1. Key Unit. Note: Check key unit ribbon connection before replacement.
The following symptoms indicate a defective key unit. Replace the control unit assembly.
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.
2. Control Unit.
The following symptoms indicate a defective control unit. Before replacing the control unit, perform
the Key unit test (Procedure L) to determine if control unit is faulty.
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 troubles 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.
Remove the outer case and check voltage between the normal open terminal of the relay RY1 and
the normal open terminal of the relay RY2 on the power unit with an A.C. voltmeter. The meter should
indicate 230 - 240 volts, if not check oven circuit.
INSTANT COOK
START
G6 G7 G8 G3
G10
G11
G12
G4 G5
G9
G2 G1
4
7
5
8
9 1
3
6
2
0
EASY
DEFROST
EXPRESS
DEFROST
TIMER
CLOCK
STOP
CLEAR
POWER
LEVEL
JACKET
POTATO
DINNER
PLATE
FROZEN
VEGETABLES
FRESH
VEGETABLES
PIE
PIZZA
RICE-PASTA
BEVERAGE
Pin
NO. G12 Pin
NO. G1
Key unit ribbon cable
Key unit (Membrane Switch) front view