Sharp R-206 (serv.man2) Service Manual ▷ View online
R-206(G)
R-206(SL)
R-206(W)
R-206(SL)
R-206(W)
11
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
M
RELAY TEST
N
PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD (PWB) IS OPEN
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin No. 3 of the 2 pin connector (A) and the
common terminal of the relay RY2 on the control unit with an A.C. voltmeter.
The meter should indicate 220 volts, if not check oven circuit.
common terminal of the relay RY2 on the control unit with an A.C. voltmeter.
The meter should indicate 220 volts, if not check oven circuit.
Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
DC. voltage indicated .......... Defective relay.
DC. voltage not indicated .... Check diode which is connected to the relay coil. If diode is good,
DC. voltage not indicated .... Check diode which is connected to the relay coil. If diode is good,
control unit is defective.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
Approx. 12.0V D.C.
Oven lamp / Turntable motor / Fan motor
RY2
Approx. 11.0V D.C.
Power transformer
CARRY OUT 4R CHECKS.
In this service manual, troubleshooting by unit replacement is described according to the symptoms
indicated.
Control unit.
The following symptoms indicate a defective control unit.
indicated.
Control unit.
The following symptoms indicate a defective control unit.
a) When rotating the potentiometer, the power level can not be selected.
b) Cooking is not possible.
b) Cooking is not possible.
To protect the electronic circuits, this model is provided with a fine foil pattern added to the input circuit
on the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide
given below for repair.
Problem: POWER ON.
CARRY OUT 3D CHECKS.
on the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide
given below for repair.
Problem: POWER ON.
CARRY OUT 3D CHECKS.
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated voltage is not applied between Pin
Check supply voltage and oven power cord.
No. 3 of the 2 pin connector (A) and the
common terminal of the relay RY1.
2
Only pattern at “a” is broken.
*Insert jumper wire J1 and solder.
3
Pattern at “a” and “b” are broken.
*Insert the coil RCILF2003YAZZ between “c” and “d”.
NOTE: *At the time of making these repairs,
make a visual inspection of the
varistor. Check for burned damage.
If any abnormal condition is detected,
replace the defective parts.
varistor. Check for burned damage.
If any abnormal condition is detected,
replace the defective parts.
CARRY OUT 4R CHECKS.
D71
R75
(F1)
(J2)
D1
(J1)
a
b
c
d
D70
R-206(G)
R-206(SL)
R-206(W)
R-206(SL)
R-206(W)
12
The control unit consists of the following circuits as shown in the control unit circuit.
The principal functions of these circuits and their related signals are explained below.
Control Unit
Control unit consists of LSI, reset circuit, power source circuit, relay circuit and synchronizing signal circuit.
1) Reset Circuit
The principal functions of these circuits and their related signals are explained below.
Control Unit
Control unit consists of LSI, reset circuit, power source circuit, relay circuit and synchronizing signal circuit.
1) Reset Circuit
This circuit generates a signal which resets the LSI to the initial state when power is supplied.
2) Potentiometer Circuit
The circuit makes setting of the power level by variable resistance.
3) Power Source Circuit
This circuit generates voltage necessary in the control unit from the AC line voltage. In addition, the synchronizing
signal is available in order to compose a basic standard time in the clock circuit.
signal is available in order to compose a basic standard time in the clock circuit.
Symbol
Voltage
Application
VDD
+5V
LSI(IC-1)
VSS
0V
LSI(IC-1)
4) Relay Circuit
To drive the magnetron, fan motor, turntable motor and light the oven lamp.
5) Synchronizing Signal Circuit
The power source synchronizing signal is available in order to compose a basic standard time in the clock circuit. It
accompanies a very small error because it works on commercial frequency.
accompanies a very small error because it works on commercial frequency.
CONTROL UNIT ASSEMBLY
OUTLINE OF CONTROL UNIT
R-206(G)
R-206(SL)
R-206(W)
R-206(SL)
R-206(W)
13
Pin No.
Signal
I/O
Description
1
VDD
IN
Power source voltage: 5V.
Connected to 5V.
Connected to 5V.
2
VSS
IN
Power source voltage: 0V.
Connected to 0V.
Connected to 0V.
3
XIN
IN
Internal clock oscillation frequency input setting.
The internal clock frequency is generated by connecting the capacitor and resistor
to XIN.
The internal clock frequency is generated by connecting the capacitor and resistor
to XIN.
4
XOUT
OUT
Terminal not used.
5
CNVSS
IN
Connected to VSS through resistor.
6
RESET
IN
Auto clear terminal.
Signal is inputted to reset the LSI to the initial state when power is supplied.
Signal is inputted to reset the LSI to the initial state when power is supplied.
7
AIN1
IN
Signal coming from potentiometer.
Voltage from potentiometer is converted into the power level by the A/D converter
built into the LSI.
Voltage from potentiometer is converted into the power level by the A/D converter
built into the LSI.
8
AIN0
IN
Cooking start detection terminal.
When “H” level is inputted to AIN0, cooking starts.
When “H” level is inputted to AIN0, cooking starts.
9
D3
OUT
Signal to allow Magnetron high-voltage circuit to be drived.
While the signal (Sqrare Waveform) is generat-
ing from D3, the Magnetron high-voltage circuit
is allowed to be drived.
While the signal (Sqrare Waveform) is generat-
ing from D3, the Magnetron high-voltage circuit
is allowed to be drived.
10
D2
OUT
Signal to check the model.
11
D1
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay (RY1). The
signal holds “L” level during microwave cooking
and “H” level while not cooking. In other cook-
ing modes (70%, 50%, 30%, 10%) the signal
turns to “H” level and “L” level in repetition
according to the power level.
To turn on and off the cook relay (RY1). The
signal holds “L” level during microwave cooking
and “H” level while not cooking. In other cook-
ing modes (70%, 50%, 30%, 10%) the signal
turns to “H” level and “L” level in repetition
according to the power level.
12
D0
OUT
Terminal not used.
13
INT
IN
Signal to synchronize LSI with commercial power source frequency.
This is basic timing for all real time processing of LSI.
This is basic timing for all real time processing of LSI.
14-16
P12-P10
OUT
Terminal not used.
17-20
P03-P00
IN
Terminal to change the Models and functions.
DESCRIPTION OF LSI
The I/O signal of the LSI are detailed in the following table.
20 msec
During cooking
H
L
ON/OFF time ratio in Micro
cooking
(a. 32second time base)
cooking
(a. 32second time base)
MICRO
ON
OFF
COOK
100%
32sec.
0sec.
70%
24sec.
8sec.
50%
18sec.
14sec.
30%
12sec.
20sec.
10%
6sec.
26sec.
20 msec
H : 5V
L : 0V
R-206(G)
R-206(SL)
R-206(W)
R-206(SL)
R-206(W)
14
1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the
circuits. When handling these parts, the following pre-
cautions should be strictly followed. CMOS LSI have
extremely high impedance at its input and output
terminals. For this reason, it is easily influenced by the
surrounding high voltage power source, static electric-
ity charge in clothes, etc., and sometimes it is not fully
protected by the built-in protection circuit.
In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap
circuits. When handling these parts, the following pre-
cautions should be strictly followed. CMOS LSI have
extremely high impedance at its input and output
terminals. For this reason, it is easily influenced by the
surrounding high voltage power source, static electric-
ity charge in clothes, etc., and sometimes 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 con-
taining them in aluminium foil.
taining them in aluminium foil.
2) When soldering, ground the technician as shown in
the figure and use grounded soldering iron and
work table.
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.
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 MI-
THE HIGH VOLTAGE TRANSFORMER OF THE MI-
CROWAVE OVEN IS STILL LIVE DURING SERV-
ICING AND PRESENTS A HAZARD .
ICING 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 insulat-
ing tape. After servicing, be sure to replace the
leads to their original locations.
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 insulat-
ing tape. After servicing, be sure to replace the
leads to their original locations.
A. On some models, the power supply cord between
the touch control panel and the oven itself is so short
that the two can't be separated.
that the two can't be separated.
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.
(sensor-related ones included) of the touch control
panel while keeping it connected to the oven.
B. On some models, the power supply cord between
the touch control panel and the oven proper is so
long enough that they may be separated from each
other.
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
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
SERVICING
panel, checking them is possible if the dummy
resistor(s) with resistance equal to that of the con-
trols are used.
resistor(s) with resistance equal to that of the con-
trols 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 termi-
nal of the touch control panel, then it is possible to
check and repair the controls 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).
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 termi-
nal of the touch control panel, then it is possible to
check and repair the controls 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 as-
sembly.
1) Soldering iron: 30W
sembly.
1) Soldering iron: 30W
(It is recommended to use a soldering iron with a
grounding terminal.)
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 control
unit, remove the aluminium foil applied for prevent-
ing static electricity.
ing 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.
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.
approx. 1M ohm
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