Sharp R-8740 (serv.man17) Service Manual ▷ View online
R-8740M - 37
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. GRILL KEY PRESSED THREE TIMES.
4. START KEY PRESSED.
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. GRILL KEY PRESSED THREE TIMES.
4. START KEY PRESSED.
Figure O-4 Oven Schematic - Convection Cooking Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. CONVECTION TEMPERATURE SELECTED
4. START KEY PRESSED.
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. CONVECTION TEMPERATURE SELECTED
4. START KEY PRESSED.
NOTE: *INDICATES COMPONENTS WITH POTENTIALS ABOVE 250V
NOTE: *INDICATES COMPONENTS WITH POTENTIALS ABOVE 250V
Figure O3(c). Oven Schematic - Grill Cooking Condition (TOP AND BOTTOM mode)
SCHEMATIC DIAGRAMS
R-8740M
C1
C3
STOR
THERMI-
B2
B1
SWITCH
STOP
UNIT
CONTROL
F1:FUSE
*CAPACITOR
F2:FUSE
EARTH
*MAGNETRON
*POWER
TRANSFORMER
BLU
BRN
*ASYMMETRIC
RECTIFIER
*H.V. RECTIFIER
NEUTRAL
LIVE
NOISE SUPPRESSION COIL
NOISE
FILTER
/15
/15
G-Y/15
0.22 F/250V
N
L
10M/0.5W
4700u/250V
4700u/250V
680K/0.5W
GRILL HEATER (TOP)
OVEN
THERMAL
CUT-OUT
OVEN LAMP
OL
F8A
TM
T
MOTOR
TURNTABLE
CUT-OUT
THERMAL
MG
230V-240V 50Hz
N.C
SWITCH
MONITOR
20A
MONIT'D
LATCH
SWITCH
MOTOR
CONVECTION
CM
BOTTOM HEATER
FAN MOTOR
FM
RY4
A1
A3
A5
A9
A11
RY7
RY5
RY1
RY3
RY2
N.O
COM
N.O
COM
N.O
COM
1.07uF 2100V
R-8740M
C1
C3
STOR
THERMI-
B2
B1
SWITCH
STOP
UNIT
CONTROL
F1:FUSE
*CAPACITOR
F2:FUSE
EARTH
*MAGNETRON
*POWER
TRANSFORMER
BLU
BRN
*ASYMMETRIC
RECTIFIER
*H.V. RECTIFIER
NEUTRAL
LIVE
NOISE SUPPRESSION COIL
NOISE
FILTER
/15
/15
G-Y/15
0.22 F/250V
N
L
10M/0.5W
4700u/250V
4700u/250V
680K/0.5W
GRILL HEATER (TOP)
OVEN
THERMAL
CUT-OUT
OVEN LAMP
OL
F8A
TM
T
MOTOR
TURNTABLE
CUT-OUT
THERMAL
MG
230V-240V 50Hz
N.C
SWITCH
MONITOR
20A
MONIT'D
LATCH
SWITCH
MOTOR
CONVECTION
CM
BOTTOM HEATER
FAN MOTOR
FM
RY4
A1
A3
A5
A9
A11
RY7
RY5
RY1
RY3
RY2
N.O
COM
N.O
COM
N.O
COM
1.07uF 2100V
R-8740M - 38
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. DUAL COOKING KEY PRESSED THREE TIMES.
4. START KEY PRESSED.
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. DUAL COOKING KEY PRESSED THREE TIMES.
4. START KEY PRESSED.
NOTE: *INDICATES COMPONENTS WITH POTENTIALS ABOVE 250V
Figure O5(b). Oven Schematic - Dual Cooking Condition (MICROWAVE AND BOTTOM GRILL mode)
C1
C3
STOR
THERMI-
B2
B1
SWITCH
STOP
UNIT
CONTROL
F1:FUSE
*CAPACITOR
F2:FUSE
EARTH
*MAGNETRON
*POWER
TRANSFORMER
BLU
BRN
*ASYMMETRIC
RECTIFIER
*H.V. RECTIFIER
NEUTRAL
LIVE
NOISE SUPPRESSION COIL
NOISE
FILTER
/15
/15
G-Y/15
0.22 F/250V
N
L
10M/0.5W
4700u/250V
4700u/250V
680K/0.5W
GRILL HEATER (TOP)
OVEN
THERMAL
CUT-OUT
OVEN LAMP
OL
F8A
TM
T
MOTOR
TURNTABLE
CUT-OUT
THERMAL
MG
230-240v 50Hz R-8740M
N.C
SWITCH
MONITOR
20A
MONIT'D
LATCH
SWITCH
MOTOR
CONVECTION
CM
BOTTOM HEATER
FAN MOTOR
FM
RY4
A1
A3
A5
A9
A11
RY7
RY5
RY1
RY3
RY2
N.O
COM
N.O
COM
N.O
COM
1.07uF 2100V
Figure O-5(a) Oven Schematic-Dual Cooking Condition (MICROWAVE AND TOP GRILL mode)
NOTE: *INDICATES COMPONENTS WITH POTENTIALS ABOVE 250V
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. DUAL COOKING KEY PRESSED TWICE.
4. START KEY PRESSED.
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. DUAL COOKING KEY PRESSED TWICE.
4. START KEY PRESSED.
SCHEMATIC DIAGRAMS
C1
C3
STOR
THERMI-
B2
B1
SWITCH
STOP
UNIT
CONTROL
F1:FUSE
CAPACITOR
F2:FUSE
EARTH
*MAGNETRON
*POWER
TRANSFORMER
BLU
BRN
*ASYMMETRIC
RECTIFIER
*H.V. RECTIFIER
NEUTRAL
LIVE
NOISE SUPPRESSION COIL
NOISE
FILTER
/15
/15
G-Y/15
0.22 F/250V
N
L
10M/0.5W
4700u/250V
4700u/250V
680K/0.5W
GRILL HEATER (TOP)
OVEN
THERMAL
CUT-OUT
OVEN LAMP
OL
F8A
TM
T
MOTOR
TURNTABLE
CUT-OUT
THERMAL
MG
230-240v 50Hz R-8740M
N.C
SWITCH
MONITOR
20A
MONIT'D
LATCH
SWITCH
MOTOR
CONVECTION
CM
BOTTOM HEATER
FAN MOTOR
FM
RY4
A1
A3
A5
A9
A11
RY7
RY5
RY1
RY3
RY2
N.O
COM
N.O
COM
N.O
COM
1.07uF 2100V
R-8740M - 39
PICTORIAL DIAGRAM
Figure S-1. Pictorial Diagram
BLU
WHT
BLK
WHT
OVEN THERMAL
CUT-OUT
MG. THERMAL
CUT-OUT
OVEN LAMP
BRN
BLK
BLU
1
BLK
2
3
ORG
4
5
WHT
6
7
8
9
BLU
COM
GRY
BLK
BLU
GRY
GRY
BLU
N.C.
NC
COM
(SW2)STOP
SWITCH
NO
COM
TOP GRILL
HEATING ELEMENT
BOTTOM
HEATING
ELEMENT
WHT
RED
WHT
BRN
BLU
GRN
GRN
GRN
BLU
TURNTABLE
MOTOR
T/C TRANSFORMER
(SW3)MONITOR
SWITCH
(SW1)MONITORED
LATCH
SWITCH
ORG
BLU
WHT
BRN
BLK
RED
ORG
RED
BRN
BLU
WHT
CN-A
1
CN-B
2
RED
GRN
RED
WHT
BLU
ORG
ORG
NOISE FILTER
L
TP
F 8 A
TL
RED
20 A
WHT
N
ORG
ORG
WHT
FAN MOTOR
CONVECTION MOTOR
GRY
WHT
HIGH VOLTAGE COMPONENTS
G–Y
POWER SUPPLY CORD
NEUTRAL
LIVE
EARTH
THERMISTOR
1
3
2
1
RY2
RY4
RY3
CONTROL PANEL
CN-B
RY5
RY7
1
12
CN-C
CN-D
WH-C
CN-G
RY1
2
3
1
BLK
BLK
CN-C
MAGNETRON
H.V.WIRE B
H.V.WIRE A
H.V.
CAPACITOR
H.V.
RECTIFIER
ASYMMETRIC RECTIFIER
HIGH VOLTAGE TRANSFORMER
RED
BLU
ORG
BLK
BLK
WHT
1
2
1
11
BRN
11
1
WHT
BLK
1
6
R-8740M - 40
CONTROL PANEL CIRCUIT DIAGRAM
Figure S-2. R-87340M Control Panel Circuit
+
–
+
+
–
–
+
–
A 1
LD1
T1
1
4
ab
c
d
6
8
Back Light
D1
D1-4
1N4005
Q4
2SB1238
Q40
DTA143ES
Q2
DTA143ES
Q26
DTA143ES
Q27
DTA143ES
Q22
DTD143ES
Q25 DTA143ES
Q21 DTA143ES
I-1
IZA091DR
M38223M4
Q23 DTA143ES
D26 1N4005
DOOR
OVEN THERMISTOR
NOTE : IF NOT SPECIFIED
: 1/4W
±
5%
: 1SS270A
: 0.1
µ
/ 16v
CN-B
CN-D
CN-A
WH-A
21
WH-A
R9 1k
Q24 DTA143ES
Q3
2SB1238
Q1
DTA123ES
VC
GND
CN-C
WH-C
6
5
4
3
2
1
D2
D4
R1 360 1w
AC230V
50Hz
CONVECTION
MOTOR
FAN
MOTOR
BOTTOM
HEARTING
ELEMENT
TOP
HEARTING
ELEMENT
OVEN LAMP
TURNTABLE
MOTOR
HIGH
VOLTAGE
TRANSFORMER
R2 360 1w
R92 15k
R93 12kF
COOKING MODE INDICATOR
R30 15k
R12 4.7k
64
80
25
SEG8
VL3
P41
26
P40
VCC
A0
A1
A2
VSS
SCL
TEST
TEST
SDA
27
RESET
28
P71
29
P70
30
XIN
31
XOUT
32
VSS
33
P27
34
P26
35
P25
36
P24
37
P23
38
P22
39
P21
40
P20
79
COM0
78
COM1
77
COM2
76
COM3
75
AVSS
74
VREF
73
VCC
72
SEG0
71
SEG1
70
SEG2
69
SEG3
68
SEG4
67
SEG5
66
SEG6
65
SEG7
1
VL2
2
VL1
3
AN7
4
AN6
5
AN5
6
AN4
7
AN3
8
AN2
9
P61
10
P60
11
P57
12
P56
13
P55
14
P54
15
P53
16
P52
17
P51
18
P50
19
P47
20
P46
21
P45
22
P44
23
INT1
24
INT0
63
SEG9
62
SEG10
61
SEG11
60
P34
59
P35
58
P36
57
P37
56
P00
55
P01
54
P02
53
P03
52
P04
51
P05
50
P06
49
P07
48
P10
47
P11
46
P12
45
P13
44
P14
43
P15
42
P16
41
P17
CF1
CST4.00MGW
(J8)
D3
10G471K
C1 0.1µ
/50v
C20 0.1
µ
/50v
CR60
CN-C
R95 15k
I-2
R90
300kF
C21
10
µ
/35v
RY2
RY3
RY1
RY4
RY7
RY5
C3
0.1µ
/50v
C2 1000µ
/35v
C6 10µ
/35v
C91 10µ
/35v
C92
C7 0.1µ
/50v
S12
C1
C2
C3
C2
C3
S11
S10
S9
S8
S7
S6
S5
S4
S3
S2
S1
S10
S9
S8
S7
S6
S5
S4
S3
S2
S1
VRS1
(J1)
SP1
(J2)
(J4)
(J6)
(J3)
(J5)
(J7)
R40 3.3k
R10 240
R98 360F
R96 2.7k
R97 10k
R94 100
ZD1 HZ5C-2
R5 4.7k
R31 4.7k
D30
D22
D23
D21
D24
D27
D25
ZD3
HZ20-1
R4 4.7k
R81
1.5k
R82
1.5k
R83
1.5k
R84
1.5k
LD7
CONV
LD6
MICRO
LD8
TOP
GRILL
LD9
BOTTOM
GRILL
8
642
9
7
5
3
21
13
R6 10k
R68 15k
R7 10k
R8 10k
C5
C30
C4
C90
ZD2
HZ4A2
LD2
LD3
LD4
A 9
A 5
A 7
A 3
A 1
COM
N.O.
COM
N.O.
COM
N.O.
4
5
25
790
46
8
1
3
6
789
1
0
11
12
3
2
1
R69 15k
R70 15k
R71 15k
R72 15k
R73 15k
TIME
REDUCE
MEMORY
MANUAL
MICROWAVE
CONVECTION
BOTTOM
GRILL
SOUND
TOP
GRILL
STOP
START
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