Sharp R-4G75M (serv.man7) Service Manual ▷ View online
27
R-4G75(W)M
R-4G75(B)M
R-4G75(B)M
DOOR FILM
Removal
1. Tear the door film from the door panel.
2. Now, the door film is free.
1. Tear the door film from the door panel.
2. Now, the door film is free.
Installation
1. Put the adhesive tape on the backing film of the door film
1. Put the adhesive tape on the backing film of the door film
as shown in Fig. 8.
2. Tear the backing film by pulling the adhesive tape.
3. Put the pasted side of the door film on the door panel.
3. Put the pasted side of the door film on the door panel.
Figure C-8. Door film
Door film
Backing film
Adhesive tape
CHOKE COVER REMOVAL
1. Insert an iron plate(thickness of about 0.5mm) or flat type
1. Insert an iron plate(thickness of about 0.5mm) or flat type
screw driver to the gap between the choke cover and
door panel as shown figure to free the engaged part. The
protect sheet may be used not to damage the door panel.
door panel as shown figure to free the engaged part. The
protect sheet may be used not to damage the door panel.
2. Lift up the choke cover, now choke cover is free.
FLAT TYPE
SCREW-DRIVER
SCREW-DRIVER
PROTECT BY TAPE
FLAT TYPE
SCREW-DRIVER
SCREW-DRIVER
DOOR
PANEL
PANEL
CHOKE
COVER
COVER
Figure C-7. Choke Cover Removal
28
R-4G75(W)M
R-4G75(B)M
R-4G75(B)M
MICROWAVE MEASUREMENT
After adjustment of door latch switches, monitor switch and
door are completed individually or collectively, the following
leakage test must be performed with a survey instrument and
it must be confirmed that the result meets the requirements
of the performance standard for microwave oven.
door are completed individually or collectively, the following
leakage test must be performed with a survey instrument and
it must be confirmed that the result meets the requirements
of the performance standard for microwave oven.
REQUIREMENT
The safety switch must prevent microwave radiation emis-
sion in excess of 5mW/cm2 at any point 5cm or more from
external surface of the oven.
The safety switch must prevent microwave radiation emis-
sion in excess of 5mW/cm2 at any point 5cm or more from
external surface of the oven.
PREPARATION FOR TESTING:
Before beginning the actual test for leakage, proceed as
follows;
1. Make sure that the test instrument is operating normally
Before beginning the actual test for leakage, proceed as
follows;
1. Make sure that the test instrument is operating normally
as specified in its instruction booklet.
Important:
Survey instruments that comply with the requirement for
instrumentations as prescribed by the performance
standard for microwave ovens must be used for testing.
Important:
Survey instruments that comply with the requirement for
instrumentations as prescribed by the performance
standard for microwave ovens must be used for testing.
Recommended instruments are:
NARDA 8100
NARDA 8200
HOLADAY HI 1500
SIMPSON 380M
NARDA 8100
NARDA 8200
HOLADAY HI 1500
SIMPSON 380M
2. Place the oven tray into the oven cavity.
3. Place the load of 275
3. Place the load of 275
±
15ml of water initially at 20
±
5
°
C
in the center of the oven tray. The water container should
be a low form of 600 ml beaker with inside diameter of
approx. 8.5cm and made of an electrically non-conductive
material such as glass or plastic.
The placing of this standard load in the oven is important
not only to protect the oven, but also to insure that any
leakage is measured accurately.
be a low form of 600 ml beaker with inside diameter of
approx. 8.5cm and made of an electrically non-conductive
material such as glass or plastic.
The placing of this standard load in the oven is important
not only to protect the oven, but also to insure that any
leakage is measured accurately.
4. Close the door and turn the oven ON with the timer set for
several minutes. If the water begins to boil before the
survey is completed, replace it with 275ml of cool water.
survey is completed, replace it with 275ml of cool water.
5. Move the probe slowly (not faster that 2.5cm/sec.) along
the gap.
6. The microwave radiation emission should be measured
at any point of 5cm or more from the external surface of
the oven.
the oven.
mW cm
2
mW cm
2
Microwave leakage measurement at 5 cm distance
SHARP
29
R-4G75(W)M
R-4G75(B)M
R-4G75(B)M
TEST DATA AT A GLANCE
Parts
Value / Data
Fuse
13A / 250V
Fuse
M8A / 250V
Monitor resistor
0.8
Ω
20W
Thermal cut-out (MG)
125
°
C
Thermal cut-out (OVEN)
160
°
C
Thermal cut-out (GRILL)
150
°
C
Oven lamp
200–250 V 25W E14
High voltage capacitor
1.2
µ
F AC 2100V
Magnetron
Filament < 1
Ω
Filament – chassis
∞
ohm.
Power transformer
Filament winding < 1
Ω
Secondary winding Approx. 82
Ω
Primary winding Approx. 1.3
Ω
TEST POINT ON CONTROL UNIT
Resistance (Disconnect the
In/Out put terminal
Test Point
Volt
power plug and close the door.)
Input terminal (Power supply)
A3–A5
240V
Approx. 905
Ω
.
Input terminal (Stop switch)
B1–B2
–
Shorted
Output terminal (Oven lamp,
A1–A3
240V
Approx. 195
Ω
.
Fan motor, Turntable motor)
Output terminal (Power transformer)
NO. of RY2–A3
240V
Approx. 1.6
Ω
.
Output terminal (Earth)
B2–Chassis
–
Shorted
Output terminal
NO. of RY3–A3
240V
Approx. 65.3
Ω
.
(Grill heater)
WARNING: DISCONNECT THE PLUG WHEN MEASURING RESISTANCE.
30
R-4G75(W)M
R-4G75(B)M
R-4G75(B)M
SCEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. CLOCK APPEARS ON DISPLAY
1. DOOR CLOSED
2. CLOCK APPEARS ON DISPLAY
NOTE: * Parts with potentials above 250V
SCEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. COOKING TIME PROGRAMMED.
3. START KEY TOUCHED
1. DOOR CLOSED
2. COOKING TIME PROGRAMMED.
3. START KEY TOUCHED
Figure O-1. Oven Schematic-OFF Condition
NOTE: * Parts with potentials above 250V
Figure O-2. Oven Schematic-Microwave Cooking Condition
240V~50Hz
BLU / 15
BRN / 15
G–Y / 15
EARTH
0.22µ / 250V
FUSE 13A
NOISE SUPPRESSION COIL
10M / 0.5W
680K / 0.5W
0.0047µ / 250V
0.0047µ / 250V
THERMAL
CUT-OUT
160°C
(OVEN)
MONITOR
RESISTOR
0.8 / 20W
OVEN LAMP
FM
TURNTABLE MOTOR
FAN MOTOR
THERMAL
CUT-OUT
130°C~150°C
(GRILL)
2ND
LATCH
SWITCH
THERMAL
CUT-OUT
125°C (MG.)
STOP
SWITCH
* HIGH VOLTAGE TRANSFORMER
* ASYMMETRIC
RECTIFIER
* CAPACITOR
1.2µ
AC2100V
* H.V. RECTIFIER
* MAGNETRON
OL
L
N
GRILL HEATING ELEMENT
B2
B1
A1
COM
COM
RY-3
RY-2
NOISE
FILTER
MONITOR SWITCH
A3
FUSE
M8A
N.O
N.O
TTM
A5
RY-1
PRIMARY
LATCH
SWITCH
THERMAL
CUT-OUT
125°C
(MAG.)
F1
F2
F3
AH. SENSOR
CONTROL UNIT
240V~50Hz
BLU / 15
BRN / 15
G–Y / 15
EARTH
0.22µ / 250V
FUSE 13A
NOISE SUPPRESSION COIL
10M / 0.5W
680K / 0.5W
0.0047µ / 250V
0.0047µ / 250V
THERMAL
CUT-OUT
160°C
(OVEN)
MONITOR
RESISTOR
0.8 / 20W
OVEN LAMP
FM
TURNTABLE MOTOR
FAN MOTOR
THERMAL
CUT-OUT
130°C~150°C
(GRILL)
2ND
LATCH
SWITCH
THERMAL
CUT-OUT
125°C (MG.)
STOP
SWITCH
* HIGH VOLTAGE TRANSFORMER
* ASYMMETRIC
RECTIFIER
* CAPACITOR
1.2µ
AC2100V
* H.V. RECTIFIER
* MAGNETRON
OL
L
N
GRILL HEATING ELEMENT
B2
B1
A1
COM
COM
RY-3
RY-2
NOISE
FILTER
MONITOR SWITCH
A3
FUSE
M8A
N.O
N.O
TTM
A5
RY-1
PRIMARY
LATCH
SWITCH
THERMAL
CUT-OUT
125°C
(MAG.)
F1
F2
F3
AH. SENSOR
CONTROL UNIT
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