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Model
R-652M
Pages
24
Size
445.23 KB
Type
PDF
Document
Service Manual
Brand
Device
Home Appliance / Microwave Oven
File
r-652m.pdf
Date

Sharp R-652M Service Manual ▷ View online

9
R-652M -
20.0 msec.
During cooking
H : GND
L : -5V
100P
H : GND
L : -5V
H : GND
L : -5V
70P
ON
ON
OFF
OFF
OFF
24 sec.
8 sec.
20.0 msec.
H : GND
L : -5V
(Grill or dual)
ON
OFF
During
cooking
L
GND
H.
15
P53
OUT
Oven lamp, fan motor and turntable motor driving signal
To turn on and off shut off relay
(RY1). The square waveform voltage
is delivered to the RY1 driving circuit,
RY2 and RY3 control circuit.
16
P52
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay
(RY3).  The signals holds "L" level
during microwave cooking and "H"
level while not cooking. In other
cooking modes (variable cooking) the
signal turns to "H" level and "L" level
in repetition according to the power
level.
(ON and OFF times for other power level.)
17
P51
OUT
Grill heating element driving signal
To turn on and off the grill heating
element relay (RY2). "L" level during
grill cooking or dual cooking; "H" level
otherwise.
18
P50
OUT
Terminal not used.
19
P47
OUT
Terminal not used.
20
P46
IN
Signal coming from touch key.
When either G12 line on key matrix is touched, a corresponding signal out
of P20 - P27 will be input into P46. When no key is touched, the signal is
held at "H" level.
21
P45
IN
Signal similar to P46.
When either G11 line on key matrix is touched, a corresponding signal will
be input into P45.
22
P44
IN
Signal similar to P46.
When either G10 line on key matrix is touched, a corresponding signal will
be input into P44.
23
P43
IN
Signal similar to P46.
When either G9 line on key matrix is touched, a corresponding signal will be
input into P43.
24
INT0
IN
Signal synchronized with commercial power source frequency.
This is the basic timing for time
processing of LSI.
LSI(IZA954DR)
The I/O signal of the LSI(IZA954DR) are detailed in the following table.
Pin No.
Signal
I/O
Description
25
P41
OUT
Terminal not used.
26
P40
IN
Connected to VC through the pull-down resistor R90.
27
RESET
IN
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied.
Temporarily set "L" level the moment power is applied, at this time the LSI is
reset. Thereafter set at "H" level.
28-29
P71-P70
OUT
Terminal not used.
30
XIN
IN
Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation
circuit with respect to XIN terminal.
31
XOUT
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of XOUT.
32
VSS
IN
Power source voltage: -5.0V.
VC voltage of power source circuit input.
  DESCRIPTION OF LSI
10
R-652M -
LSI(IZA954DR)
The I/O signal of the LSI(IZA954DR) are detailed in the following table.
Pin No.
Signal
I/O
Description
33
P27
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G1 line keys on key matrix is touched.
34
P26
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G2 line keys on key matrix is touched.
35
P25
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G3 line keys on key matrix is touched.
36
P24
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G4 line keys on key matrix is touched.
37
P23
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G5 line keys on key matrix is touched.
38
P22
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G6 line keys on key matrix is touched.
39
P21
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G7 line keys on key matrix is touched.
40
P20
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G8 line keys on key matrix is touched.
41-56
P17-P00
OUT
Terminal not used.
57-60
P37-P34
OUT
Terminal not used.
61-72
SEG11-SEG0
OUT
Segment data signal.
Connected to LCD.
The relation between signals are as follows:
LSI signal (Pin No.) LCD (Pin No.)
LSI signal (Pin No.) LCD (Pin No.)
SEG 11 (61) ............................ S12
SEG   5 (67) .............................. S6
SEG 10 (62) ............................ S11
SEG   4 (68) .............................. S5
SEG   9 (63) ............................ S10
SEG   3 (69) .............................. S4
SEG   8 (64) ............................   S9
SEG   2 (70) .............................. S3
SEG   7 (65) ............................   S8
SEG   1 (71) .............................. S2
SEG   6 (66) ............................   S7
SEG   0 (72) .............................. S1
73/74
VCC/VREF
IN
Connected to GND.
75
AVSS
IN
Connected to VC.
76
COM3
OUT
Terminal not used.
77
COM2
OUT
Common data signal.
Connected to LCD signal C3.
78
COM1
OUT
Common data signal.
Connected to LCD signal C2.
79
COM0
OUT
Common data signal.
Connected to LCD signal C1.
80
VL3
IN
Power source voltage input terminal.
Standard voltage for LCD.
  DESCRIPTION OF LSI
11
R-652M -
  SERVICING
approx. 1M ohm
1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the
circuits. When handling these parts, the following
precautions should be strictly followed. CMOS LSI
have extremely high impedance at its input and
output terminals. For this reason, it is easily influ-
enced by the surrounding high voltage power source,
static electricity charge in clothes, etc., and some-
times it is not fully protected by the built-in protection
circuit.
In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap
them in aluminium foil. Also wrap PW boards
containing them in aluminium foil.
2) When soldering, ground the technician as shown
in the figure and use grounded soldering iron and
work table.
2. Servicing of Touch Control Panel
We describe the procedures to permit servicing of the
touch control panel of the microwave oven and the
precautions you must take when doing so.
To perform the servicing, power to the touch control
panel is available either from the power line of the
oven itself or from an external power source.
(1) Servicing the touch control panel with power
supply of the oven :
CAUTION:
THE HIGH VOLTAGE TRANSFORMER OF THE
MICROWAVE OVEN IS STILL LIVE DURING
SERVICING AND PRESENTS A HAZARD .
Therefore, when checking the performance of the
touch control panel, put the outer cabinet on the
oven to avoid touching the high voltage trans-
former, or unplug the primary terminal (connector)
of the high voltage transformer to turn it off; the
end of such connector must be insulated with an
insulating tape. After servicing, be sure to replace
the leads to their original locations.
A.
 On some models, the power supply cord be-
tween the touch control panel and the oven
itself is so short that the two can't be sepa-
rated.
For those models, check and repair all the
controls (sensor-related ones included) of the
touch control panel while keeping it connected
to the oven.
B.
 On some models, the power supply cord be-
tween the touch control panel and the oven
proper is so long enough that they may be
separated from each other.
For those models, therefore, it is possible to
check and repair the controls of the touch
control panel while keeping it apart from the
oven proper; in this case you must short both
ends of the door sensing switch (on PWB) of
the touch control panel with a jumper, which
brings about an operational state that is
equivalent to the oven door being closed. As
for the sensor-related controls of the touch
control panel, checking them is possible if
the dummy resistor(s) with resistance equal
to that of the controls are used.
(2) Servicing the touch control panel with power
supply from an external power source:
Disconnect the touch control panel completely
from the oven proper, and short both ends of the
door sensing switch (on PWB) of the touch
control panel, which brings about an operational
state that is equivalent to the oven door being
closed. Connect an external power source to the
power input terminal of the touch control panel,
then it is possible to check and repair the con-
trols of the touch control panel; it is also possible
to check the sensor-related controls of the touch
control panel by using the dummy resistor(s).
3. Servicing Tools
Tools required to service the touch control panel
assembly.
1) Soldering iron: 30W
(It is recommended to use a soldering iron with
a grounding terminal.)
2) Oscilloscope: Single beam, frequency range:
DC - 10MHz type or more advanced model.
3) Others: Hand tools
4. Other Precautions
1) Before turning on the power source of the con-
trol unit, remove the aluminium foil applied for
preventing static electricity.
2) Connect the connector of the key unit to the
control unit being sure that the lead wires are not
twisted.
3) After aluminium foil is removed, be careful that
abnormal voltage due to static electricity etc. is
not applied to the input or output terminals.
4) Attach connectors, electrolytic capacitors, etc.
to PWB, making sure that all connections are
tight.
5) Be sure to use specified components where
high precision is required.
12
R-652M -
COMPONENT REPLACEMENT
DOOR REPLACEMENT
1.
CARRY OUT 3D CHECKS.
2.
Remove 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 to
free the engaged part.
3.
Remove door assembly by lifting and easing
it forward.
4.
On re-installation make sure the door is
parallel with the bottom line of the oven face
plate and the latch head pass through the
latch holes correctly.
5.
CARRY OUT 4R CHECKS.
NOTE : After any service to the door, the
approved microwave survey meter should be
used to assure in compliance with proper
microwave radiation standards.
Figure C-6.  Door Assembly Replacement and
Adjustment
LATCH HEAD REMOVAL
1.
Remove the choke as described in door
replacement.
2.
Unhook the spring and lift the latch head clear.
3.
Replacement, the reverse of the above.
INNER DOOR FILM
Removal
1.
Tear the door film from the door panel.
2.
Now the door film is free.
Installation
1.
Tear away the backing film.
2.
Put the pasted side of the door film on the door
panel
.
DOOR PANEL ASSEMBLY
1. Remove door assy by removing screws (4).
2. Remove Glass Stopper Screw (noting position of
stopper) and slide stopper down while lifting up.
3. Slide glass towards Glass Stopper position and then
down towards the lower edge of the door frame.
4. Lift upper edge of glass, which will now be free from
upper clips and remove from lower clips.
5. Refitting is a reversal of the above when refitting,
ensure the glass and the glass stopper is in the original
position.
1. CARRY OUT 3D CHECKS.
2. Remove the control panel assembly referring to
"CONTROL PANEL REPLACEMENT".
3. Remove the open lever from the oven cavity front plate
by removing the control panel assy.
4. Disconnect the leads from all switches.
5. Remove the one (1) screw holding the latch hook to
the oven cavity.
6. Remove the latch hook.
7. Remove the switch(s) from the latch hook by pushing
the retaining tab backwards slightly and turning the
switch(s) on the post.
8. Now, the switch(s) is free.
LATCH SWITCH, MONITOR SWITCH AND STOP SWITCH REMOVAL
Figure C-5  Switches
Latch hook
Tab
SW3:  Stop switch
SW2: Monitor switch
SW1:  Monitored latch switch
Tab
Tab
Door film
Finger tab
Backing film
DOOR ASSEMBLY
OUTER CASE
CABINET
LATCH HEADS
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