Sharp R-33ST Service Manual ▷ View online
R33ST - 15
COMPONENT REPLACEMENT AND ADJUSTMENT
REMOVAL
1. Disconnect the power supply cord.
2. Open the door slightly.
3. Remove the choke cover taking care not to break clips
2. Open the door slightly.
3. Remove the choke cover taking care not to break clips
by inserting 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 C-4 to free the
engaged parts.
or flat type screw driver to the gap between the choke
cover and door panel as shown Figure C-4 to free the
engaged parts.
4. Release choke cover from door panel.
5. Now choke cover is free.
5. Now choke cover is free.
Figure C-4. Door Disassembly
6. Release two (2) pins of door panel from two (2) holes
of upper and lower oven hinges by lifting up.
7.
1. Remove door assy by removing screws (4).
8. Release door panel from tabs of door frame and
remove door frame by sliding the door panel downward.
9. Now, door panel with inner sealer film is free.
10. Tear inner sealer film from door panel.
11. Now, door panel is free.
12. Slide latch head upward and remove it from door
10. Tear inner sealer film from door panel.
11. Now, door panel is free.
12. Slide latch head upward and remove it from door
frame with releasing latch spring from door frame and
latch head.
latch head.
13. Now, latch head and latch spring are free.
14.
14.
Remove Glass Stopper Screw (noting position of
stopper) and slide stopper down while lifting up.
stopper) and slide stopper down while lifting up.
15.
Slide glass towards Glass Stopper position and
then down towards the lower edge of the door
frame.
frame.
16.
Lift upper edge of glass, which will now be free
from upper clips and remove from lower clips.
17.
Refitting is a reversal of the above when refitting,
ensure the glass and the glass stopper is in the
original position.
original position.
RE-INSTALL
1. Re-install the outer door glass to the door frame with
the glass stopper.
2. Hold the glass stopper with the one (1) screw.
3. Re-install latch spring to the head. Re-install latch
3. Re-install latch spring to the head. Re-install latch
spring to the door frame. Re-install latch head to the
door frame.
door frame.
4. Re-install door panel to door frame by fitting tabs of
door frame to holes of door panel.
5. Put sealer film on door panel. Refer to “Inner Sealer
Film” and figure C-6, on how to handle the new film.
6. Catch two (2) pins of door panel on two (2) hole of
upper and lower oven hinges.
7. Re-install choke cover to door panel by pushing.
Note: After any service to the door;
(A) Make sure that monitored latch switch, stop
(A) Make sure that monitored latch switch, stop
switch and monitor switch are operating properly.
(Refer to chapter “Test Procedures”.).
(Refer to chapter “Test Procedures”.).
(B) An approved microwave survey meter should be
used to assure compliance with proper
microwave radiation emission limitation
standards.
microwave radiation emission limitation
standards.
10
5
4
12
8
7
9
11
3
2
1
Choke Cover
Door Frame
Putty Knife
6
After any service, make sure of the following :
1. Door latch heads smoothly catch latch hook through
latch holes and that latch head goes through center of
latch hole.
latch hole.
2. Deviation of door alignment from horizontal line of
cavity face plate is to be less than 1.0mm.
3. Door is positioned with its face pressed toward cavity
face plate.
4. Check for microwave leakage around door with an
approved microwave survey meter. (Refer to
Microwave Measurement Procedure.)
Microwave Measurement Procedure.)
Note:
The door on a microwave oven is designed to act
as an electronic seal preventing the leakage of
microwave energy from oven cavity during cook
cycle. This function does not require that door be
air-tight, moisture (condensation)-tight or light-
tight. Therefore, occasional appearance of
moisture, light or sensing of gentle warm air
movement around oven door is not abnormal
and do not of themselves, indicate a leakage of
microwave energy from oven cavity.
as an electronic seal preventing the leakage of
microwave energy from oven cavity during cook
cycle. This function does not require that door be
air-tight, moisture (condensation)-tight or light-
tight. Therefore, occasional appearance of
moisture, light or sensing of gentle warm air
movement around oven door is not abnormal
and do not of themselves, indicate a leakage of
microwave energy from oven cavity.
Figure C-5. Door Replacement
INNER
SEALER FILM
Installation
1. Tear away the backing film.
3. Put the pasted side of the inner sealer film on the door
3. Put the pasted side of the inner sealer film on the door
panel.
Pin
Pin
Lower
Oven
Hinge
Oven
Hinge
Lower Oven
Hinge
Hinge
Upper
Oven
Hinge
Oven
Hinge
Upper Oven
Hinge
Hinge
Door Panel
Choke Cover
Door film
Finger tab
Backing film
Figure C-6. Inner Sealer Film
R33ST - 16
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
emission in excess of 5mW/cm2 at any point 5cm or more
from external surface of the oven.
emission 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
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.
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.
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
R33ST - 17
SCHEMATIC DIAGRAM
Figure 0-1 Oven Schematic
SW3:
NO
COM
NO
NO
NC
TTM
OL
OVEN LAMP
TURNTABLE MOTOR
SWITCH
MONITOR
MONITORED
125fl
O
C
CUT-OUT
THERMAL
125fl
O
C
CUT-OUT
THERMAL
CONTROL UNIT
NOISE FILTER
UNIT
B1
B2
A3
SW
STOP
LATCH
SWITCH
COM.
NO.
RY2
RY1
FAN MOTOR
FM
SW1
SW2
T/C TRANSFORMER
MAGNETRON
OVEN
MAGNETRON
230-240V
EARTH
N
L
BLU
BRN
0.0033 F/250V
0.0033 F /250V
/17
/17
G-Y/17
FUSE
F8A
F8A
NOISE SUPPRESSION COIL
F1:
0.22 F /250V
680K/0.5W
10M/0.5W
1.0 F
2100VAC
CAPACITOR
RECTIFIER
ASYMMETRIC
RECTIFIER
H.V .
POWER TRANSFORMER
50Hz
A1
*INDICATES PARTS WITH POTENTIALS OVER 240V
*
*
*
*
*
A5
E7
E5
E3
E1
R33ST - 18
Figure S-3. Control Panel Circuit
CONTROL PANEL CIRCUIT DIAGRAM
+
–
+
–
+
–
+
–
E 1
E 3
WH-A
E 5
E 7
T1
AC230V 50Hz
OVEN LAMP FAN MOTOR TURNTABLE MOTOR
HIGH VOLTAGE TRANSFORMER
STOP SWITCH
510 1w
R1
510 1w
R2
D1
RY1
RY2
VRS1
a
b
c
d
C1 0.1
µ
/50v
C2 470
µ
/50v
C20
10
µ
/35v
IC1 IXA025DR
C21 0.1
µ
/50v
C6 10
µ
/35v
C7 0.1
µ
/50v
0.1
µ
/50v
C3
C4
C5
D5
D6
Q2 DTA123ES
Q1 KRA101M
Q40 KRA101M
Q21 KRA101M
Q20 KRC243M
Q22 KRA101M
Q6 2SB1238
D28 11ES1
Q3 2SB1238
(J9)
(J7)
LIQUID CRYSTAL TUBE
CONTROL UNIT
KEY UNIT
(J8)
(J6)
(J2) 4.7k
SP1
(J1)
D20
D30
D21
R12 1.5k
ZD4
HZ20-1
R40 3.3k
R8 15k
R10 15k
R9 15k
R3 4.7k
R30 15k
G11
G7
G2
G5. 9
R69 4.7k
R68 4.7k
R70 4.7k
R71 4.7k
R72 4.7k
R73 4.7k
R74 4.7k
R31 4.7k
CR60
G12
G10
G8
G6
G4
G1
G3
NOTE
: IF NOT SPECIFIED 1/4w
±
5%
: IF NOT SPECIFIED 1SS270A
: IF NOT SPECIFIED 0.01
µ
F/16v
±
5%
C30
CF1 4MHz
R5
16
R6
4.7k
R4 4.7k
ZD1 HZ5C2
ZD2
HZ4A2
LD1
LD2
LD3
LD4
LD5
A 3
A 1
B 1
B
2
A 5
NO
COM
SEG10
C1
5
10
15
20
25
30
55
60
65
70
75
80
35
45
85
90
95
50
VL1
C2
VL2
VL3
COM0
COM1
P73
P72
P71
P70
RESET
XCIN
XCOUT
XIN
XOUT
VSS
P27
P26
P25
P24
P23
P22
P21
P20
P17
P16
COM2
COM3
AVSS
VREF
VCC
SEG0
SEG1
SEG2
SEG3
SEG4
SEG5
SEG6
SEG7
SEG8
SEG9
AN7
AN6
AN5
AN4
AN3
AN2
AN1
AN0
P57
P56
P55
P54
P53
P52
P51
P50
P47
P46
P45
P44
P41
P40
P77
P76
P75
P74
P43
INT0
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
SEG18
SEG19
SEG20
SEG21
SEG22
SEG23
SEG24
SEG25
SEG26
SEG27
SEG28
SEG29
SEG30
SEG31
SEG32
SEG33
P10
P11
P12
P13
P14
P15
(J3) 4.7k
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