Sharp R-8000GK Service Manual ▷ View online
R-8000GK
15
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
1.
CARRY OUT 3D CHECKS.
2. Disconnect the leads to the primary of the high voltage transformer.
3. Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.
4. After that procedure, re-connect the power supply cord.
5. Remove the outer case and check voltage between Pin Nos. 1 and 9 of the 5 pin connector (CN-D) on the
3. Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.
4. After that procedure, re-connect the power supply cord.
5. Remove the outer case and check voltage between Pin Nos. 1 and 9 of the 5 pin connector (CN-D) on the
control unit with an A.C. voltmeter. The meter should indicate the rated voltage, if not check oven circuit.
Shut-off, Cook and Heater Relays 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, oven cooking
or speed cooking condition.
Shut-off, Cook and Heater Relays 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, oven cooking
or speed cooking condition.
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. 27.0V D.C.
Oven lamp / Turntable motor
RY2 (COOK)
Approx. 25.0V D.C.
Power transformer
RY3
Approx. 25.0V D.C.
Jet motor
RY5
Approx. 25.0V D.C.
Fan motors
RY6
Approx. 25.0V D.C.
Jet motor capacitor
6. CARRY OUT 4R CHECKS.
W
RELAY TEST
1.
CARRY OUT 3D CHECKS.
2. Disconnect the wire leads from the solid-state relay.
3. Measure the resistance between the terminals as described in the following table, with an ohmmeter.
3. Measure the resistance between the terminals as described in the following table, with an ohmmeter.
Terminals
Resistance
Between 1 and 2
Approx. 50M
Ω
Between 3 and 4
Approx. 1.3M
Ω
4. If the meter does not indicate above resistance, replace the solid-state relay.
5. CARRY OUT 4R CHECKS.
5. CARRY OUT 4R CHECKS.
X
SOLID-STATE RELAY TEST
To protect the electronic circuits, this model is provided with a fuse added to the primary on the PWB.
1. Fuse 1 check and repairs.
1. Fuse 1 check and repairs.
1) CARRY OUT 3D CHECKS.
2) If the Fuse 1 is blown, replace power unit.
3) Make a visual inspection of the varistor. Check for burned damage. If the varistor has been burned, replace
2) If the Fuse 1 is blown, replace power unit.
3) Make a visual inspection of the varistor. Check for burned damage. If the varistor has been burned, replace
the power unit.
4) Examine the touch control transformer with a tester for the presence of layer short-circuit (check the
primary coil resistance which is approximately 275
Ω ± 10%). If any abnormal condition is detected,
replace the touch control transformer.
5) CARRY OUT 4R CHECKS.
2. Follow the troubleshooting guide given below, if indicator does not light up after above check and repairs are
finished.
1) CARRY OUT 3D CHECKS.
2) Disconnect the leads to the primary of the high voltage transformer.
3) Ensure that these leads remain isolated from other components and oven chassis by using insulation
1) CARRY OUT 3D CHECKS.
2) Disconnect the leads to the primary of the high voltage transformer.
3) Ensure that these leads remain isolated from other components and oven chassis by using insulation
tape.
4) After that procedure, re-connect the power supply cord.
5) Follow the troubleshooting guide given below for repair.
5) Follow the troubleshooting guide given below for repair.
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present to power
Check supply voltage and oven power cord.
terminal of CPU connecter (CN-D).
2
The rated AC voltage is present at primary
Touch control transformer or secondary circuit defective.
side of touch control transformer.
Check and replace touch control transformer, power
unit or CPU unit.
unit or CPU unit.
6) CARRY OUT 4R CHECKS.
Y
PROCEDURES TO BE TAKEN WHEN THE FUSE 1 ON THE PRINTED WIRING BOARD
(PWB) IS OPEN.
(PWB) IS OPEN.
Solid-state relay
2
1
4
3
R-8000GK
16
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
The touch control section consists of the following units as shown
in the touch control panel circuit.
in the touch control panel circuit.
(1) Tact switch circuit on the CPU unit and the control unit (switch unit).
(2) Control Unit (The control unit consists of Power unit and CPU unit.)
The principal functions of these units and the signals communi-
cated among them are explained below.
cated among them are explained below.
Tact Switch Circuit
The tact switch circuit is composed of a matrix, signals AN0-AN7
generated in the LSI are sent to the tact switches. When a tact
switch is touched, a signal is completed through the tact switch
circuit and passed back to the LSI through PB0-PB3 to perform
the function that was requested.
The tact switch circuit is composed of a matrix, signals AN0-AN7
generated in the LSI are sent to the tact switches. When a tact
switch is touched, a signal is completed through the tact switch
circuit and passed back to the LSI through PB0-PB3 to perform
the function that was requested.
Control Unit
Control unit consists of LSI, power source circuit, synchronizing
signal circuit, reset circuit, buzzer circuit, temperature measure-
ment circuit, relay watching circuit, input voltage watching circuit
and indicator circuit.
Control unit consists of LSI, power source circuit, synchronizing
signal circuit, reset circuit, buzzer circuit, temperature measure-
ment circuit, relay watching circuit, input voltage watching circuit
and indicator circuit.
1) LSI (IC-1)
This LSI controls the temperature measurement signal, tact
switch strobe signal, relay driving signal and indicator signal.
And also LSI watches the relay operation and the primary
input voltage.
switch strobe signal, relay driving signal and indicator signal.
And also LSI watches the relay operation and the primary
input voltage.
2) Power Source Circuit
This circuit generates the voltage necessary for the control
unit from the AC line voltage.
unit from the AC line voltage.
3) Synchronizing Signal Circuit
The power source synchronizing signal is available in order to
compose a basic standard time in the clock circuit. It incorporates
a very small error because it works on commercial frequency.
compose a basic standard time in the clock circuit. It incorporates
a very small error because it works on commercial frequency.
4) Reset Circuit
A circuit to generate a signals which resetting the LSI to the
initial state when power is applied.
initial state when power is applied.
5) Buzzer Circuit
The buzzer is responds to signals from the LSI to emit
noticing sounds (tact switch touch sound and completion
sound).
noticing sounds (tact switch touch sound and completion
sound).
6) Temperature Measurement Circuit : (OVEN THERMISTOR)
The temperature in the oven cavity is sensed by the thermistor.
The variation of resistance according to sensed temperature
is detected by the temperature measurement circuit and the
result applied to LSI. The LSI uses this information to control
the relay and display units.
The variation of resistance according to sensed temperature
is detected by the temperature measurement circuit and the
result applied to LSI. The LSI uses this information to control
the relay and display units.
7) Relay Operation Watching Circuit
This circuit watches so that the three (3) relays for the top
heating element, the side heating element and the power
transformer do not operate at the same time. This circuit
consists of the transistor Q24 - Q27 and resistors R23 - R26.
heating element, the side heating element and the power
transformer do not operate at the same time. This circuit
consists of the transistor Q24 - Q27 and resistors R23 - R26.
8) Input Voltage Watching Circuit
This circuit watches the primary input voltage.
9) Door Sensing Switch
A switch to inform the LSI if the door is open or closed.
10) Relay Circuit
To drive the magnetron, heating elements, fan motor, jet
motor, turntable motor and light the oven lamp.
motor, turntable motor and light the oven lamp.
11) Indicator Circuit
Indicator element is a Fluorescent Display.
Basically, a Fluorescent Display is triode having a cathode,
a grid and an anode. Usually, the cathode of a Fluorescent
Display is directly heated and the filament serves as cathode.
The Fluorescent Display has 10-digits, 42-segments are
used for displaying figures.
Basically, a Fluorescent Display is triode having a cathode,
a grid and an anode. Usually, the cathode of a Fluorescent
Display is directly heated and the filament serves as cathode.
The Fluorescent Display has 10-digits, 42-segments are
used for displaying figures.
12) Memory Processor (IC-2)
This is a memory IC, responsible for memory function.
DESCRIPTION OF LSI (IC-1)
LSI(IC-1):
The I/O signals of the LSI(IC-1) are detailed in the following table.
The I/O signals of the LSI(IC-1) are detailed in the following table.
Pin No.
Signal
I/O
Description
1
AN5
OUT
Tact switch strobe signal.
Signal applied to tact switch section (SW1, SW4, SW7, SW10).
Signal applied to tact switch section (SW1, SW4, SW7, SW10).
2
AN4
OUT
Turminal not used.
3
AN3
OUT
Tact switch strobe signal.
Signal applied to tact switch section (SW14, SW18, SW22).
Signal applied to tact switch section (SW14, SW18, SW22).
4
AN2
OUT
Tact switch strobe signal
Signal applied to tact switch section (SW13, SW17, SW21).
Signal applied to tact switch section (SW13, SW17, SW21).
5
AN1
OUT
Tact switch strobe signal.
Signal applied to tact switch section (SW12, SW16, SW20).
Signal applied to tact switch section (SW12, SW16, SW20).
6
AN0
OUT
Tact switch strobe signal.
Signal applied to tact switch section (SW11, SW15, SW19, SW23).
Signal applied to tact switch section (SW11, SW15, SW19, SW23).
7
AN15
IN
Primary input voltage watching terminal.
The LSI is watching the primary input voltage through this terminal.
The LSI is watching the primary input voltage through this terminal.
8-10
AN14-AN12
IN
Input terminal to change the specification according to the model.
11
AN11
IN
Temperature measurement input: OVEN THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermistor, this
input is converted into temperature by the A/D converter built into the LSI.
By inputting DC voltage corresponding to the temperature detected by the thermistor, this
input is converted into temperature by the A/D converter built into the LSI.
12
AN10
IN
Input signal which communicates the door open/close information to LSI.
Door closed; “H” level
Door closed; “H” level
µµ(0V).
Door opened; “L” level signal(-5V).
R-8000GK
17
Pin No.
Signal
I/O
Description
13-14
AN9-AN8
IN
Turminal not used.
15
P83
OUT
Timing signal output terminal for temperature measurement (OVEN THERMISTOR).
“L” level (-5V) : Thermistor OPEN timing.
“H” level (GND) : Temperature measuring timing.
“H” level (GND) : Temperature measuring timing.
16
P82
OUT
Oven lamp and turntable motor driving signal. (Square Waveform : 50Hz)
To turn on and off the shut-off relay(RY1). The
square waveform voltage is delivered to the
relay(RY1) driving circuit.
To turn on and off the shut-off relay(RY1). The
square waveform voltage is delivered to the
relay(RY1) driving circuit.
17
CNVSS
IN
Power source voltage: -5V.
VC voltage of power source circuit input.
VC voltage of power source circuit input.
18
RESET
IN
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied. Temporarily set to
“L” level the moment power is applied, at this time the LSI is reset. Thereafter set at “H” level.
Signal is input to reset the LSI to the initial state when power is applied. Temporarily set to
“L” level the moment power is applied, at this time the LSI is reset. Thereafter set at “H” level.
19
P81
OUT
Top heating element driving signal.
To operate the solid-state relay for driving the top heating element.
To operate the solid-state relay for driving the top heating element.
20
P80
OUT
Side heating element driving signal.
To operate the solid-state relay for driving the top heating element.
To operate the solid-state relay for driving the top heating element.
21
VSS
IN
Power source voltage: -5V.
VS voltage of power source circuit input.
VS voltage of power source circuit input.
22
Xin
IN
Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to Xout terminal.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to Xout terminal.
23
Xout
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of Xin.
Output to control oscillation input of Xin.
24
VCC
IN
Power source voltage: 0V.
VC voltage of power source circuit input. Connected to GND.
VC voltage of power source circuit input. Connected to GND.
25
P77
OUT
Signal to sound buzzer.
A: Tact switch touch sound.
B: Completion sound.
C: When the oven stops so that the food can be
checked in Automatic cooking mode.
26
P76
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay(RY2). In 100%
power operation, the signals holds “L” level
during microwave cooking and “H” level while
not cooking. In other cooking modes (90%,
80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%,
0%) the signal turns to “H” level and “L” level in
repetition according to the power level.
power operation, the signals holds “L” level
during microwave cooking and “H” level while
not cooking. In other cooking modes (90%,
80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%,
0%) the signal turns to “H” level and “L” level in
repetition according to the power level.
27
P75
OUT
Cooling fan motor driving signal.
To turn on and off shut-off relay(RY5). “L” level
during fan motor driving; “H” level otherwise
during fan motor driving; “H” level otherwise
28
P74
OUT
Turminal not used.
29
P73
OUT
Jet motor driving signal.
To turn on and off shut-off relay(RY3). “L” level
during jet motor driving “H” level otherwise
To turn on and off shut-off relay(RY3). “L” level
during jet motor driving “H” level otherwise
30
P72
OUT
Control signal to turn over the rotatory direction of the jet motor.
31
P71
IN
Signal to synchronize LSI with commercial power source frequency.
This is the basic timing for all real time process-
ing of LSI.
This is the basic timing for all real time process-
ing of LSI.
32
P70
IN/OUT
Memory (EEPROM) data input/output.
33
P67
OUT
Terminal to input the program to LSI.
During cooking
L
H
20 msec.
A
B
C
H: GND
L
0.1 sec
2.0 sec
1.0 sec
1.0 sec
Microwave cooking mode
Microwave cooking with
other cooking mode
other cooking mode
VARI MODE
ON TIME OFF TIME ON TIME OFF TIME
100% power
32 sec.
0 sec.
54sec.
0ec.
90% power
30 sec.
2 sec.
49sec.
5sec.
80% power
26 sec.
6 sec.
45sec.
9sec.
70% power
24 sec.
8 sec.
40sec.
14sec.
60% power
22 sec.
10 sec.
36sec.
18sec.
50% power
18 sec.
14 sec.
29sec.
25sec.
40% power
16 sec.
16 sec.
24sec.
30sec.
30% power
12 sec.
20 sec.
18sec.
36sec.
20% power
8 sec.
24 sec.
13sec.
41sec.
10% power
6 sec.
26 sec.
9sec.
45sec.
0% power
0 sec.
32 sec.
0sec.
54sec.
ON
OFF
During
fan motor driving
L
GND
H.
ON
OFF
During
Jet motor
driving
L
GND
H.
20 msec.
H : GND
L (-5V)
R-8000GK
18
Pin No.
Signal
I/O
Description
34
P66
IN
Terminal to input the program to LSI.
35
P65
OUT
Memory (EEPROM) clock out.
36
P64
IN/OUT
Terminal to input the program to LSI.
37-88
FLD51-FLD0
OUT
Segment data signals.
The relation between signals and indicator are as follows:
The relation between signals and indicator are as follows:
Signal (
Pin No.
) Segment (
Pin No.
) Signal (
Pin No.
) Segment (
Pin No.
) Signal(
Pin No.
) Segment(
Pin No.
)
FLD 0 (88) ------------ 10G(45)
FLD 18 (70) ------------- P9 (67)
FLD 36 (52) -------------- P30 (19)
FLD 1 (87) ------------- 9G (46)
FLD 19 (69) ----------- P10 (68)
FLD 37 (51) -------------- P29 (20)
FLD 2 (86) ------------- 8G (47)
FLD 20 (68) ----------- P11 (69)
FLD 38 (50) -------------- P28 (21)
FLD 3 (85) ------------- 7G (48)
FLD 21 (67) ----------- P12 (70)
FLD 39 (49) -------------- P27 (22)
FLD 4 (84) ------------- 6G (49)
FLD 22 (66) ----------- P13 (71)
FLD 40 (48) -------------- P26 (23)
FLD 5 (83) ------------- 5G (50)
FLD 23 (65) ----------- P14 (72)
FLD 41 (47) -------------- P25 (24)
FLD 6 (82) ------------- 4G (51)
FLD 24 (64) ------------- P42 (7)
FLD 42 (46) -------------- P24 (25)
FLD 7 (81) ------------- 3G (52)
FLD 25 (63) ------------- P41 (8)
FLD 43 (45) -------------- P23 (26)
FLD 8 (80) ------------- 2G (53)
FLD 26 (62) ------------- P40 (9)
FLD 44 (44) -------------- P22 (27)
FLD 9 (79) ------------- 1G (54)
FLD 27 (61) ----------- P39 (10)
FLD 45 (43) -------------- P21 (28)
FLD10 (78) ------------ P1 (59)
FLD 28 (60) ----------- P38 (11)
FLD 46 (42) -------------- P20 (29)
FLD11 (77) ------------ P2 (60)
FLD 29 (59) ----------- P37 (12)
FLD 47 (41) -------------- P19 (30)
FLD12 (76) ------------ P3 (61)
FLD 30 (58) ----------- P36 (13)
FLD 48 (40) -------------- P18 (31)
FLD13 (75) ------------ P4 (62)
FLD 31 (57) ----------- P35 (14)
FLD 49 (39) -------------- P17 (32)
FLD14 (74) ------------ P5 (63)
FLD 32 (56) ----------- P34 (15)
FLD 50 (38) -------------- P16 (33)
FLD15 (73) ------------ P6 (64)
FLD 33 (55) ----------- P33 (16)
FLD 51 (37) -------------- P15 (34)
FLD16 (72) ------------ P7 (65)
FLD 34 (54) ----------- P32 (17)
FLD17 (71) ------------ P8 (66)
FLD 35 (53) ----------- P31 (18)
89
VEE
IN
Anode (segment) of Fluorescent Display light-up voltage: -30V.
VEE voltage of power source circuit input.
VEE voltage of power source circuit input.
90-92
PB6-P84
OUT
Terminal not used.
93
PB3
IN
Signal coming from tact switches (SW10, SW23).
94
PB2
IN
Signal coming from tact switches (SW7-9, SW19-22).
95
PB1
IN
Signal coming from tact switches (SW4-6, SW15-18).
96
PB0
IN
Signal coming from tact switches (SW1-3, SW11-14).
97
AVSS
IN
A/D converter power source voltage.
The power source voltage to drive the A/D converter in the LSI.
The power source voltage to drive the A/D converter in the LSI.
98
VREF
IN
Reference voltage input terminal.
A reference voltage applied to the A/D converter in the LSI. Connected to GND.(0V)
A reference voltage applied to the A/D converter in the LSI. Connected to GND.(0V)
99
AN7
OUT
Tact switch strobe signal.
Signal applied to tact switch section (SW3, SW6, SW9).
Signal applied to tact switch section (SW3, SW6, SW9).
100
AN6
OUT
Tact switch strobe signal.
Signal applied to tact switch section (SW2, SW5, SW8).
Signal applied to tact switch section (SW2, SW5, SW8).
Memory Processor (IC-2)
Memory processor is a 16K-bit, serial memory, enabling CMOS to be erased/written electrically. This memory is constructed with 2048
registers x 8bits, enabling individual access, read and write operations to be performed. Details of input/output signal for IC2 are as
shown in the following diagram.
registers x 8bits, enabling individual access, read and write operations to be performed. Details of input/output signal for IC2 are as
shown in the following diagram.
Figure T-3 Relation between Pin Nos, and Signals
Pin No.
Signal
I/O
Description
1-3
A0-A2
IN
Connected to -5V.
4
VSS
IN
Connected to -5V.
5
SDA
IN/OUT
Serial data input/output : input/outputs data to IC1.
6
SCL
IN
Clock signal input : input/outputs sireal data at every one pulse.
7
WP
IN
Connected to -5V.
8
VCC
IN
Connected to GND.
A0
A1
A2
VSS
VCC
WP
SCL
SDA
TOP VIEW
1
2
3
4
8
7
6
5
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