Sharp R-884 (serv.man2) Service Manual ▷ View online
R-884M - 29
REMOVAL
1. Disconnect the oven from the power supply.
2. Push the open button and open the door slightly.
3. Insert an putty knife (thickness of about 0.5mm) into the
2. Push the open button and open the door slightly.
3. Insert an putty knife (thickness of about 0.5mm) into the
gap between the choke cover and door frame as shown
in Figure C-7 to free engaging parts.
in Figure C-7 to free engaging parts.
4. Release choke cover from door panel.
5. Now choke cover is free.
5. Now choke cover is free.
DOOR REPLACEMENT
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
Figure C-7. Door Disassembly
6. Lift the door upwards.
7. Now, door sub assembly is free from oven cavity.
8. Remove the four (4) screws holding the door panel to
7. Now, door sub assembly is free from oven cavity.
8. Remove the four (4) screws holding the door panel to
the door frame.
9. Release door panel from six (6) tabs of door frame by
sliding door panel upward.
10.Now, door panel is free.
11.Slide latch head upward and remove it from door
11.Slide latch head upward and remove it from door
frame with releasing latch spring from door frame and
latch head.
latch head.
12.Now, latch head and latch spring are free.
13.Remove the two (2) screws holding the glass stopper to
13.Remove the two (2) screws holding the glass stopper to
the door frame.
14.Remove the glass stopper from the door frame.
15.Slide the front door glass leftwards and then slide
15.Slide the front door glass leftwards and then slide
upwards to release the tabs holding it.
16.Now, the front door glass is free
RE-INSTALL
1. Re-install the front door glass to the door frame as
1. Re-install the front door glass to the door frame as
follows.
a) Insert the upper edge of the front door glass into the
a) Insert the upper edge of the front door glass into the
six (6) tabs of the door frame.
b) Slide the front door glass downwards and insert the
lower edge of the front door glass into the six (6) tabs
of the door frame.
of the door frame.
c) Slide the front door glass rightwards and insert the
right edge of the front door glass into the one (1) tab
of the door frame.
of the door frame.
2. Re-install the glass stopper to the door frame as follows.
a) Re-install the glass stopper to the door frame so that
the two (2) holes of the glass stopper meet the two
(2) pins of the door frame.
(2) pins of the door frame.
b) Hold the glass stopper to the door frame with the two
(2) screws.
3. Re-install the latch spring to the latch head. Re-install
the latch spring to the door frame. Re-install latch head
to door frame.
to door frame.
4. Re-install door panel to door frame by fitting six (6) tabs
of door frame to six (6) holes of door panel.
5. Hold the door panel to the door frame with four (4)
screws.
6. Locate door panel hinge pins into cavity hinge location
holes.
7. Re-install choke cover to door panel by clipping into
position.
Note: After any service to the door;
(A) Make sure that the monitor switch, monitored
latch switch and stop switch are operating prop-
erly. (Refer to chapter "Test Procedures".).
erly. (Refer to chapter "Test Procedures".).
(B) An approved microwave survey meter should be
used to assure compliance with proper micro-
wave radiation emission limitation standards.
(Refer to Microwave Measurement Procedure.)
wave radiation emission limitation standards.
(Refer to Microwave Measurement Procedure.)
After any service, make sure of the following :
1. Door latch heads smoothly catch latch hook through
1. Door latch heads smoothly catch latch hook through
latch holes and that latch head goes through centre 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 Micro-
wave Measurement Procedure.)
wave 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
airtight, 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 en-
ergy 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
airtight, 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 en-
ergy from oven cavity.
Figure C-8. Door Replacement
NOTE: When carrying out any repair to the door,
do not bend or warp the slit choke (tabs on
the door panel assembly) to prevent
microwave leakage.
Door frame
Choke cover
Putty knife
PIN
PIN
LOWER
OVEN HINGE
OVEN HINGE
UPPER
OVEN HINGE
OVEN HINGE
LOWER
OVEN HINGE
OVEN HINGE
CHOKE COVER
DOOR
PANEL
PANEL
DOOR SUB
ASSEMBLY
ASSEMBLY
SLIT CHOKE
R-884M - 30
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
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
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
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
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 accu-
racy can be traced to National Physical Laboratory
Standards.
racy 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.
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.
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.
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.
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.
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
b) across the face of the door
c) across any vents in the oven's sides, rear or top
Whilst the maximum leakage permitted in BS EN 60335-2-25 is 50 W/m
2
(equivalent to 5 mW/cm
2
), it is not normal
to detect any significant leakage, and therefore any detected leakage should be investigated.
Dotted line indicates the path taken by the leakage detec-
tor.
tor.
R-884M - 31
Note:
AC CORD CONNECTION
BRN :
AC CORD CONNECTION
BRN :
BROWN
BLU :
BLUE
G-Y :
GREEN AND YELLOW STRIPE
/15 :
SECTIONAL AREA OF 1.5mm
2
MIN.
"
"
Indicates components with potential
above 250 V.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. "ENERGY SAVED MODE" APPEARS ON DISPLAY.
1. DOOR CLOSED.
2. "ENERGY SAVED MODE" APPEARS ON DISPLAY.
Figure O-1(c) Oven Schematic-OFF Condition after the oven door is closed.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. " . O" APPEARS ON DISPLAY.
1. DOOR CLOSED.
2. " . O" APPEARS ON DISPLAY.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. PLUGGED IN OVEN.
3. NOTHING APPEARS ON DISPLAY.
1. DOOR CLOSED.
2. PLUGGED IN OVEN.
3. NOTHING APPEARS ON DISPLAY.
Figure O-1(a) Oven Schematic-OFF Condition right after the oven is plugged in.
Figure O-1(b) Oven Schematic-OFF Condition when the oven door is opened.
OL
CM
TTM
OVEN LAMP
CONVECTION
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.07 F
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1
E3
E5
E7
A1
B2
C3
C1
A5
B1
(SW2)STOP SWITCH
(SW1)MONITORED LATCH SWITCH
THERMISTOR
MG.
THERMAL
CUT-OUT
THERMAL
CUT-OUT
OVEN
THERMAL
CUT-OUT
THERMAL
CUT-OUT
(SW3)MONITOR
SWITCH
SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22
/250V
FUSE F1 20A
FUSE F2 F8A
NOISE
FILTER
FILTER
L
N
230 - 240V ~ 50Hz
BRN/15
BLU/15
G-Y/15
EARTH
LIVE
NEUTRAL
NC.
NC.
ASYMMETRIC
RECTIFIER
RECTIFIER
RY6
RY1
RY2
RY3
RY4
FM
1
-
OL
CM
TTM
OVEN LAMP
CONVECTION
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.07 F
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1
E3
E5
E7
A1
B2
C3
C1
A5
B1
(SW2)STOP SWITCH
(SW1)MONITORED LATCH SWITCH
THERMISTOR
MG.
THERMAL
CUT-OUT
THERMAL
CUT-OUT
OVEN
THERMAL
CUT-OUT
THERMAL
CUT-OUT
(SW3)MONITOR
SWITCH
SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22
/250V
FUSE F1 20A
FUSE F2 F8A
NOISE
FILTER
FILTER
L
N
230 - 240V ~ 50Hz
BRN/15
BLU/15
G-Y/15
EARTH
LIVE
NEUTRAL
NC.
NC.
ASYMMETRIC
RECTIFIER
RECTIFIER
RY6
RY1
RY2
RY3
RY4
FM
1
-
OL
CM
TTM
OVEN LAMP
CONVECTION
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.07 F
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1
E3
E5
E7
A1
B2
C3
C1
A5
B1
(SW2)STOP SWITCH
(SW1)MONITORED LATCH SWITCH
THERMISTOR
MG.
THERMAL
CUT-OUT
THERMAL
CUT-OUT
OVEN
THERMAL
CUT-OUT
THERMAL
CUT-OUT
(SW3)MONITOR
SWITCH
SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22
/250V
FUSE F1 20A
FUSE F2 F8A
NOISE
FILTER
FILTER
L
N
230 - 240V ~ 50Hz
BRN/15
BLU/15
G-Y/15
EARTH
LIVE
NEUTRAL
NC.
NC.
ASYMMETRIC
RECTIFIER
RECTIFIER
RY6
RY1
RY2
RY3
RY4
FM
1
-
SCHEMATIC DIAGRAMS
R-884M - 32
Figure O-2 Oven Schematic-Microwave cooking Condition
Figure O-3(a) Oven Schematic-Grill cooking Condition (TOP GRILL mode)
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. START KEY TOUCHED.
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. START KEY TOUCHED.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. TOP GRILL MODE SELECTED.
4. START KEY TOUCHED.
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. TOP GRILL MODE SELECTED.
4. START KEY TOUCHED.
OL
CM
TTM
OVEN LAMP
CONVECTION
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.07 F
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1
E3
E5
E7
A1
B2
C3
C1
A5
B1
(SW2)STOP SWITCH
(SW1)MONITORED LATCH SWITCH
THERMISTOR
MG.
THERMAL
CUT-OUT
THERMAL
CUT-OUT
OVEN
THERMAL
CUT-OUT
THERMAL
CUT-OUT
(SW3)MONITOR
SWITCH
SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22
/250V
FUSE F1 20A
FUSE F2 F8A
NOISE
FILTER
FILTER
L
N
230 - 240V ~ 50Hz
BRN/15
BLU/15
G-Y/15
EARTH
LIVE
NEUTRAL
NC.
NC.
ASYMMETRIC
RECTIFIER
RECTIFIER
RY6
RY1
RY2
RY3
RY4
FM
1
-
OL
CM
TTM
OVEN LAMP
CONVECTION
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.07 F
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1
E3
E5
E7
A1
B2
C3
C1
A5
B1
(SW2)STOP SWITCH
(SW1)MONITORED LATCH SWITCH
THERMISTOR
MG.
THERMAL
CUT-OUT
THERMAL
CUT-OUT
:
OVEN
THERMAL
CUT-OUT
OVEN
THERMAL
CUT-OUT
(SW3)MONITOR
SWITCH
SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22
/250V
FUSE F1 20A
FUSE F2 F8A
NOISE
FILTER
FILTER
L
N
230 - 240V ~ 50Hz
BRN/15
BLU/15
G-Y/15
EARTH
LIVE
NEUTRAL
NC.
NC.
ASYMMETRIC
RECTIFIER
RECTIFIER
RY6
RY1
RY2
RY3
RY4
FM
1
-
SCHEMATIC DIAGRAMS
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