Sharp R-774M (serv.man2) Service Manual ▷ View online
R-774M - 29
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
air-tight, moisture (condensation)-tight or light-
tight. Therefore, occasional appearance of mois-
ture, 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
air-tight, moisture (condensation)-tight or light-
tight. Therefore, occasional appearance of mois-
ture, 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.
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
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.
tabs 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
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.
two (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.
10
5
4
12
8
7
9
11
3
2
1
Choke Cover
Door Frame
Putty Knife
6
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
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
R-774M - 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 stand whose accuracy
can be traced to National Physical Laboratory Stand-
ards.
can be traced to National Physical Laboratory Stand-
ards.
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-774M - 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 stand whose accuracy
can be traced to National Physical Laboratory Stand-
ards.
can be traced to National Physical Laboratory Stand-
ards.
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-774M - 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 stand whose accuracy
can be traced to National Physical Laboratory Stand-
ards.
can be traced to National Physical Laboratory Stand-
ards.
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.
