Sharp R-950A Service Manual

R-950A
17
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
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.
d) Proper temperature measurement is not obtained.
f 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
contacts 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 connector). 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.
O KEY UNIT TEST
1
2
3
4
5
67
890
STOP
CLEAR
AUTO
GRILL
AUTO
BAKE
KITCHEN
TIMER
SIMUL
GRILL
SIMUL
CONVEC
EASY
DEFROST
LESS
POWER
LEVEL
40˚C
70˚C
130˚C
150˚C
160˚C
180˚C
200˚C
220˚C 230˚C
250˚C
CONVEC
GRILL
PREHEAT
CLOCK
HELP
AUTO
REHEAT
AUTO
COOK
AUTO
ROAST
INSTANT COOK
START
MORE
G 1
G 2
G 3
G 4
G 5 G 6 G 7 G 8 G 9 G10 G11 G12
Remove the outer case and check voltage between Pin No 7 of the 4-pin connector (A) and the
common terminal of the relay RY1 on the control unit with an A.C. voltmeter. The meter should indicate
220 volts, if not check oven circuit.
Shut-off, Cook and Heater Relay Test
These relays are operated by D.C. voltage.
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation or
convection 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.
RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS
RY1 APPROX. 21.0V D.C. Oven lamp / Turntable motor
RY2(COOK) APPROX. 20.0V D.C. Power transformer
RY3(HEATER) APPROX. 20.0V D.C. Convection heater
RY4 APPROX. 21.0V D.C. Damper motor
RY5 APPROX. 21.0V D.C. Convection motor
RY6 APPROX. 21.0V D.C. Cooling fan motor
RY7 APPROX. 21.0V D.C. Grill heater
P RELAY TEST

Sharp R-950A Specifications

Power

ac line voltage	220 V
microwave frequency	2450 MHz
ac power required (microwave)	1.6 kW
ac power required (convection)	1.6 kW
ac power required (grill)	1.05 kW
ac power required (simul)	3.15 kW

Oven Specifications

oven capacity	41 litre
output power (microwave)	900 W
output power (convection heater)	1500 W
output power (grill heater)	1000 W

Weight and Dimensions

width	627 mm
height	378 mm
depth	492 mm
cavity width	410 mm
cavity height	245 mm
cavity depth	410 mm
weight	29 kg