Sharp R-752M (serv.man2) Service Manual ▷ View online
13
752M -
MICROWAVE MEASUREMENT
After any repair, the microwave oven must be checked for microwave leakage to ensure continued safe operation. BS EN
60335-2-25 specifies that the maximum permitted leakage with a load of 275 ml is 50 W/m
60335-2-25 specifies that the maximum permitted leakage with a load of 275 ml is 50 W/m
2
(equivalent to 5 mW/cm
2)
at
a distance of 5 cm from the oven.
PREPARATION
The following items are required to carry out this test:-
1. A low form of 600 ml beaker made from an electrically non-conductive material, such as glass or plastic, with an inside
1. A low form of 600 ml beaker made from an electrically non-conductive material, such as glass or plastic, with an inside
diameter of approximately 8.5 cm. This must contain 275
±
15 ml of water, at an initial temperature of 20
±
2˚C.
2. A leakage detector which has been calibrated within the preceding 12 months to a standard whose accuracy can be
traced to National Physical Laboratory Standards.
Recommended instruments are:
Apollo “XI”
Celtec “A100”
Celtec “A100”
Before commencing the test, check that the leakage detector is functioning and adjusted according to the manufacturer’s
instructions, and any spacers are fitted to ensure that measurement is taken 5cm from the surface of the oven.
instructions, and any spacers are fitted to ensure that measurement is taken 5cm from the surface of the oven.
PROCEDURE
1. Place the beaker containing the water load in the oven cavity at the centre of the turntable. The placing of this standard
load in the oven is important, not only to protect the oven, but also to ensure that any leakage it is not disguised by too
large a load absorbing energy.
large a load absorbing energy.
2. Close the oven door, and with the power level set to FULL, turn the oven ON with the timer set for a few minutes
operation. Should the water begin to boil before the test has been completed, it should be replaced.
3. As shown in the diagram below, move the probe slowly (not faster than 2.5 cm/sec.);-
a) around the edge of the door following the gap
b) across the face of the door
c) across any vents in the oven’s sides, rear or top
a) around the edge of the door following the gap
b) across the face of the door
c) across any vents in the oven’s sides, rear or top
Dotted line indicates the path by the leakage detector.
Whilst the maximum leakage permitted in BS60335 2-25 is 50 /W/m
2
(equivalent to 5 W/cm
2
),it is not normal to detect any
significant leakage, and therefore any detected leakage should be investigated.
14
752M -
Figure O-1 Oven Schematic
WIRING DIAGRAM
FUSE
F2:
H.V.
F
*
*
*
*
*
-130 C
MONITORED
SWITCH
MONITOR
LATCH
SWITCH
SW3
F8A
230-240V 50 H
Z
*INDICATES PARTS WITH POTENTIALS OVER 240V
F1:
1.07
2100VAC
RECTIFIER
ASYMMETRIC
CAPACITOR
H.V.
POWER TRANSFORMER
RECTIFIER
MAGNETRON
H.V.
H.V.
15A
0.0047 F/250V
0.0047 F/250V
680K/0.5W
10M/0.5W
NOISE SUPPRESSION COIL
F/250V
0.22
FUSE
G-Y/15
/15
/15
BRN
BLU
L
N
EARTH
BLU
GRILL HEATER
FM
OL
150C
CUT-OUT
THERMAL
GRILL
TTM
RED
SW1:
SW2:
A5
B1
B2
A3
CONTROL UNIT
RY2
RY1
A1
NO.
COM.
NO.
COM.
RY3
NO.
COM.
/20
WHT
BLK
/20
BRN
WHT
20
20
ORG
/18
/18
BLK
BLU
RED
/18
/18
WHT
BLK
/18
RED
/18
WHT
BLU
BRN
/20
BLU
/18
BLU
/20
GRY
STOP
MAG
THERMAL
CUT OUT
CUT OUT
125 C
WHT
160 C
CUT OUT
THERMAL
OVEN
RED
SWITCH
15
752M -
WIRING DIAGRAM
Figure S-2. Power Unit Circuit
+
–
B 1
C 1
C 2
C 3
C 4
C 6
C 7
C 5
C 8
C 9
C11
C12
B 2
A 1
A 3
NO
COM
NO
COM
STOP
SWITCH
SWITCH
STOP
SWITCH
SWITCH
NC
GND
VC
BUZZER
VR
INT
CN-C
13 WIRE HARNESS
AC230-240V
50Hz
50Hz
OVEN LAMP
TURNTABLE
MOTOR
FAN MOTOR
TURNTABLE
MOTOR
FAN MOTOR
HIGH
VOLTAGE
TRANSFORMER
VOLTAGE
TRANSFORMER
GRILL
HEATING
ELEMENT
HEATING
ELEMENT
R3
130 1w
130 1w
D1
S1NB10
S1NB10
R1 430 2w
R2 470 1w
T1
GND
a
b
c
d
VRS1
C1 470
µ
/50v
SP1
(J1)
10G471K
RY1
RY3
C10
C13
NO
COM
RY2
CN-B
CN-A
16
752M -
WIRING DIAGRAM
Figure S-3.Control Panel Circuit
+
—
+
—
C 4
GND
C 3
GND
VC
INT
VR
BUZZER
BUZZER
NC
OVEN LAMP
TURNTABLE
MOTOR
FAN MOTOR
TURNTABLE
MOTOR
FAN MOTOR
HIGH
VOLTAGE
TRANSFORMER
VOLTAGE
TRANSFORMER
DOOR
SWITCH
SWITCH
C 7
C 9
C 8
C 5
C 6
C13
C10
C11
C12
C 1
C 2
G 9
G10
G11
G12
G 1
41
64
1
24
IC1
RH-IZA954DR
LIQUID CRYSTAL DISPLAY
80
65
25
40
G 2
G 3
G 4
G 5
G 6
G 7
G 8
S12
S11
S10
S 9
S 8
S 7
S 6
S 5
S 4
S 3
S 2
S 1
C 3
C 2
C 1
SEG10
SEG11
P34
P35
P36
P37
P00
P01
P02
P03
P04
P05
P06
P07
P10
P11
P12
P13
P14
P15
P16
P17
SEG9
SEG8
VL2
VL1
AN7
AN6
AN5
5
10
15
20
45
50
55
60
30
35
70
75
AN4
P63
P62
AN1
P60
P57
P56
P55
CNTR0
VL3
COM0
COM1
COM2
P41
P40
RESET
P71
C1 0.1
/50v
C2 0.1
/50v
C4
R1 4.7k
R40 4.7k
R67 15k
R66 15k
R65 15k
R64 15k
R63 15k
R62 15k
R61 15k
R60 15k
R77 100k
R76 100k
R75 100k
R74 100k
R2 27
R3 4.7k
Q1
DTA143EKA
DTA143EKA
0.1
/50v
C5
0.01
/50v
C3 47
/16v
C40
0.01
/50v
P70
XIN
XOUT
VSS
P27
P26
P25
P24
P23
P22
P21
P20
COM3
AVSS
VREF
VCC
SEG0
SEG1
SEG2
SEG3
SEG4
SEG5
SEG6
SEG7
P53
P52
P51
P50
P47
P46
P45
P44
P43
INT0
D1-D2 1SS355
D1
D2
R4 1k
R5 15k
R6 15k
R7 15k
R30 3.3k
R21 1.5k
R41 15k
(J11) 4.7k
(J13) 4.7k
(J15) 4.7k
(J17) 4.7k
(J10)
(J12)
(J14)
(J16) 4.7k
R90 4.7k
R91
1M
R68 15k
R69 15k
R70 15k
R71 15k
R69 15k
R70 15k
R71 15k
RR 200
D22
1SS355
1SS355
ZD20
UDZ22B
UDZ22B
D20
DAP202U
DAP202U
NOTE
: IF NOT SPECIFIED, 1/10W – 5%
D21
1SS355
1SS355
PWB BACK PLAT
LD1-LD5
Q30
DTA143EKA
DTA143EKA
Q2
2SA1037AK
2SA1037AK
Q3
2SA1037AK
2SA1037AK
Q20
DTA143EKA
DTA143EKA
Q21
DTD143EK
DTD143EK
Q22
DTA123JKA
DTA123JKA
Q24
2SA1037AK
2SA1037AK
LD1
LD2
LD3
LD4
LD5
R8 15k
C6 0.01
/50v
330pF/50v
C63
330pF/50v
C62
330pF/50v
C61
330pF/50v
C60
C20
0.1 /50v
0.1 /50v
CF1
CST4.00MGW
CST4.00MGW
C21
10 /35v
10 /35v
C7 0.01
/50v
ZD1
UDZ4.3B
AUTO
START
AUTO
COOK
POWER
LEVEL
FRESH
FISH
JACKET
POTATOES
BOILED
POTATOES
MINCED
MEAT
FRESH
VEG.
RICE/
PASTA
CAKE
LESS
CANNED
FOOD
SPONGE
PUDDING
AUTO
DEFROST
STOP/
CLEAR
CLOCK
Kg / Lb
10 min.
Kg ¥ Lb
g ¥ oz
TIMER
1 min.
10 sec.
START
AUTO
MINUTE
MORE
CPU UNIT
KEY UNIT
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