Sharp R-246 (serv.man2) Service Manual ▷ View online
R-246(G)
R-246(SL)
R-246(W)
R-246(SL)
R-246(W)
11
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary 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, indicator does not light up.
CARRY OUT 3D CHECKS.
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, indicator does not light up.
CARRY OUT 3D CHECKS.
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present between
Check supply voltage and oven power cord.
Pin No. 3 of the 2 pin connector (A) and the
common terminal of the relay RY2.
common terminal of the relay RY2.
2
The rated AC voltage is present to primary
Low voltage transformer or secondary circuit defective.
side of low voltage transformer.
Check and repair.
3
Only pattern at "a" is broken.
*Insert jumper wire J1 and solder.
4
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 and examine the trans-
former with a tester for the presence of
layer short-circuit (check the primary coil
resistance). If any abnormal condition is
detected, replace the defective parts.
for burned damage and examine the trans-
former with a tester for the presence of
layer short-circuit (check the primary coil
resistance). If any abnormal condition is
detected, replace the defective parts.
CARRY OUT 4R CHECKS.
N
PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD (PWB) IS OPEN
BOARD (PWB) IS OPEN
M
RELAY TEST
Remove the outer case and check voltage between Pin No. 3 of the 2 pin connector (A) and common
terminal of the relay (RY2) on the control unit with an A.C. voltmeter.
The meter should indicate 230 - 240 volts, if not check oven circuit.
terminal of the relay (RY2) on the control unit with an A.C. voltmeter.
The meter should indicate 230 - 240 volts, if not check oven circuit.
RY1 and RY2 Relay Test
These relays are operated by D.C. voltage.
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
These relays are operated by D.C. voltage.
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. 15.0V D.C.
Oven lamp / Turntable motor / Cooling fan motor
RY2
APPROX. 11.0V D.C.
High voltage transformer
CARRY OUT 4R CHECKS.
G10
G 9
G 8
G 7
G 6
G 5
G 4
G 3
G 2
G 1
Express
COOK
10 sec
1 min
10 min
Express
DEFROST
POWER
WEIGHT
STOP
CLEAR
START
AUTO
MINUTE
1
P
RY1
a
b
c
d
RY2
(J1)
12
R-246(G)
R-246(SL)
R-246(W)
R-246(SL)
R-246(W)
The touch control section consists of the following units as
shown in the touch control panel circuit.
shown in the touch control panel circuit.
(1) Key Unit
(2) Control Unit
(2) Control Unit
The principal functions of these units and their related
signals are explained below.
signals are explained below.
Key Unit
The key unit is composed of a matrix, signals generated in
the LSI are sent to the key unit through R00, R01, R03,
R20 and R21.
When a key pad is touched, a signal is completed through
the key unit and passed back to the LSI through R23, K00,
K01 and K02 to perform the function that was requested.
The key unit is composed of a matrix, signals generated in
the LSI are sent to the key unit through R00, R01, R03,
R20 and R21.
When a key pad is touched, a signal is completed through
the key unit and passed back to the LSI through R23, K00,
K01 and K02 to perform the function that was requested.
Control Unit
Control unit consists of LSI, reset circuit, indicator circuit,
power source circuit, relay circuit, buzzer circuit and
synchronizing signal circuit.
Control unit consists of LSI, reset circuit, indicator circuit,
power source circuit, relay circuit, buzzer 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.
the initial state when power is supplied.
2) Indicator Circuit
This circuit consists of 4-digits, 12-segments and 3-
common electrodes using a Liquid Crystal Display.
common electrodes using a Liquid Crystal Display.
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
3) Power Source Circuit
This circuit generates voltage necessary in the control
unit from the AC line voltage. In addition, the synchro-
nizing signal is available in order to compose a basic
standard time in the clock circuit.
unit from the AC line voltage. In addition, the synchro-
nizing signal is available in order to compose a basic
standard time in the clock circuit.
Symbol
Voltage
Application
VC
-5V
LSI(IC1)
4) Relay Circuit
To drive the magnetron, fan motor, turntable motor and
light the oven lamp.
light the oven lamp.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
audible sounds (key touch sound and completion
sound).
audible sounds (key touch sound and completion
sound).
6) 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.
order to compose a basic standard time in the clock
circuit. It accompanies a very small error because it
works on commercial frequency.
7) 2nd. Interlock Relay Control Switch
A switch to “tell” the LSI if the door is open or closed.
R-246(G)
R-246(SL)
R-246(W)
R-246(SL)
R-246(W)
13
1
RESET
IN
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is supplied.
Temporarily set to “L” level the moment power is supplied, at this time the LSI is
reset. Thereafter set at “H” level.
Signal is input to reset the LSI to the initial state when power is supplied.
Temporarily set to “L” level the moment power is supplied, at this time the LSI is
reset. Thereafter set at “H” level.
2
TEST
IN
Connected to GND.
3
VSS
IN
Power source voltage: -5V.
VSS voltage of power source circuit input. Connected to VC.
VSS voltage of power source circuit input. Connected to VC.
4
OCS3
IN
Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the resistor oscillation circuit with
respect to OCS4 terminal.
The internal clock frequency is set by inserting the resistor oscillation circuit with
respect to OCS4 terminal.
5
OCS4
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of OCS3.
Output to control oscillation input of OCS3.
6
VD1
IN
Power source for oscillation circuit.
7
VDD
IN
Power source voltage input terminal.
Connected to GND.
Connected to GND.
8
AVDD
IN
A/D converter power source voltage.
The power source voltage to drive the A/D converter in the LSI. Connected to GND.
The power source voltage to drive the A/D converter in the LSI. Connected to GND.
9
AVREF
IN
A/D converter power source voltage.
The power source voltage to drive the A/D converter in the LSI. Connected to GND.
The power source voltage to drive the A/D converter in the LSI. Connected to GND.
10
AVSS
IN
Power source voltage: -5V.
AVSS voltage of power source circuit input. Connected to VC.
AVSS voltage of power source circuit input. Connected to VC.
11-13
P40-P42
IN
Terminal to change functions according to the Model.
By using the A/D converter contained in the LSI, DC voltage in accordance with the
Model in operation is applied to set up its function.
By using the A/D converter contained in the LSI, DC voltage in accordance with the
Model in operation is applied to set up its function.
14
P43
IN
To input signal which communicates the door open/close information to LSI.
Door close “H” level signal (0V). Door open “L” level (-5V).
Door close “H” level signal (0V). Door open “L” level (-5V).
15
BZ
OUT
Signal to sound buzzer (2.0 kHz).
A: key touch sound.
B: Completion sound.
A: key touch sound.
B: Completion sound.
16
R00
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and
K02 terminal while one of G6 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and
K02 terminal while one of G6 line keys on key matrix is touched.
17
R01
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and
K02 terminal while one of G5 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and
K02 terminal while one of G5 line keys on key matrix is touched.
18
R02
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and
K02 terminal while one of G4 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and
K02 terminal while one of G4 line keys on key matrix is touched.
19
R03
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and
K02 terminal while one of G3 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and
K02 terminal while one of G3 line keys on key matrix is touched.
20
P20
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01
and K02 terminal while one of G2 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01
and K02 terminal while one of G2 line keys on key matrix is touched.
21
P21
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and
K02 terminal while one of G1 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and
K02 terminal while one of G1 line keys on key matrix is touched.
22
P22
OUT
Terminal not used.
23
P23
IN
Signal similar to K02.
When either G7 line on key matrix is touched, a corresponding signal will be
input into P23.
input into P23.
DESCRIPTION OF LSI
LSI
The I/O signal of the LSI are detailed in the following table.
The I/O signal of the LSI are detailed in the following table.
Pin No.
Signal
I/O
Description
A
B
0.1 sec.
2.0 sec.
H : GND
L : -5V
H : GND
L : -5V
14
R-246(G)
R-246(SL)
R-246(W)
R-246(SL)
R-246(W)
Pin No.
Signal
I/O
Description
24
K00
IN
Signal similar to K02.
When either G8 line on key matrix is touched, a corresponding signal will be input
into K00.
When either G8 line on key matrix is touched, a corresponding signal will be input
into K00.
25
K01
IN
Signal similar to K02.
When either G9 line on key matrix is touched, a corresponding signal will be input
into K01.
When either G9 line on key matrix is touched, a corresponding signal will be input
into K01.
26
K02
IN
Signal coming from touch key.
When either G10 line on key matrix is touched, a corresponding signal out of R00,
R01, R02, R03, P20 and P21 will be input into K02. When no key is touched, the
signal is held at “H” level.
When either G10 line on key matrix is touched, a corresponding signal out of R00,
R01, R02, R03, P20 and P21 will be input into K02. When no key is touched, the
signal is held at “H” level.
27
K03
IN
Signal synchronized with commercial power source frequency.
This is the basic timing for time
processing of LSI.
processing of LSI.
28
COM0
OUT
Common data signal.
Connected to LCD (Pin No. C1)
Connected to LCD (Pin No. C1)
29
COM1
OUT
Common data signal.
Connected to LCD (Pin No. C2)
Connected to LCD (Pin No. C2)
30
COM2
OUT
Common data signal.
Connected to LCD (Pin No. C3)
Connected to LCD (Pin No. C3)
31
COM3
OUT
Terminal not used.
32-33
SEG0-SEG1
OUT
Terminal not used.
34
SEG2
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay (RY2).
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.
To turn on and off the cook relay (RY2).
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.
35
SEG3
OUT
Terminal not used.
36
SEG4
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 and
RY2 control circuit.
To turn on and off shut off relay (RY1).
The square waveform voltage is
delivered to the RY1 driving circuit and
RY2 control circuit.
37-39
SEG5-SEG7
OUT
Terminal not used.
40-51
SEG8-SEG19
OUT
Segment data signal.
Connected to LCD.
The relation between signals are as follows:
Connected to LCD.
The relation between signals are as follows:
LSI signal (Pin No.) LCD (Segment)
LSI signal (Pin No.) LCD (Segment)
SEG 8 (40) .......................... S12
SEG 14 (46) ............................ S6
SEG 9 (41) .......................... S11
SEG 15 (47) ............................ S5
SEG 10 (42) .......................... S10
SEG 16 (48) ............................ S4
SEG 11 (43) ............................ S9
SEG 17 (49) ............................ S3
SEG 12 (44) ............................ S8
SEG 18 (50) ............................ S2
SEG 13 (45) ............................ S7
SEG 19 (51) ............................ S1
52-53
VC1-VC2
IN
Power source voltage input terminal.
Standard voltage for LCD.
Standard voltage for LCD.
54
VC3
OUT
Terminal not used.
H : GND
L : -5V
OFF
ON
ON
OFF
OFF
H : GND
L : -5V
100P
70P
24 sec.
8 sec.
During cooking
L : -5V
H : GND
20.0 msec.
GND
-5V
20.0 msec.
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