Sharp R-259M (serv.man2) Service Manual ▷ View online
R259(W)
8 – 4
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light up.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.
3) Other possible troubles caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
[12] Procedure L: KEY UNIT (MEMBRANE SWITCH) TEST
1. CARRY OUT 3D CHECKS.
2. Isolate the key unit with the control panel frame to be tested.
3. Using an ohmmeter and referring to the key unit matrix indicated on the control unit circuit, check the circuit between the pins of the key unit that
correspond to the STOP/CLEAR key. When the pad is pressed, the ohmmeter should indicate short circuit. When the pad is released, the ohmme-
ter should indicate open circuit. If incorrect readings are obtained, the key unit is faulty and must be replaced. About the other pads, the above
method may be used.
ter should indicate open circuit. If incorrect readings are obtained, the key unit is faulty and must be replaced. About the other pads, the above
method may be used.
4. CARRY OUT 4R CHECKS.
[13] Procedure M: RELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between the normal open terminal of the relay RY1 and the normal open 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.
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.
DC. voltage indicated ................................... Defective relay.
DC. voltage not indicated ............................. Check diode which is connected to the relay coil. If diode is good, control unit is defective.
CARRY OUT 4R CHECKS.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
Approx. 12.6V D.C.
Oven lamp / Turntable motor / Cooling fan motor
RY2
Approx. 12.3V D.C.
High voltage transformer
Pin NO. G1
Pin NO. G10
Key unit ribbon
cable
cable
Key unit (Membrane Switch) front view
POWER
LEVEL
10min.
CHICKEN
QUARTERS
WHOLE
POULTRY
MEAT
JOINT
(TIME)
(TIME)
(WEIGHT)
(WEIGHT)
STOP
CLEAR
10sec.
1min.
ROAST
POULTRY
ROAST
PORK
ROAST
BEEF / LAMB
AUTO
COOK
START
AUTO MINUTE
KITCHEN TIMER
CLOCK SET
G1
G2
G3
G4
G5
G6
G7
G8
G9
G10
R259(W)
8 – 5
[14] Procedure N: PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE
PRINTED WIRING BOARD (PWB) IS OPEN
PRINTED WIRING BOARD (PWB) IS OPEN
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.
foil pattern is open, follow the troubleshooting guide given below for repair.
Problem: POWER ON, indicator does not light up.
CARRY OUT 3D CHECKS.
NOTE: *At the time of making these repairs, make a visual inspection of the varistor.
Check for burned damage and examine the transformer 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.
presence of layer short-circuit (check the primary coil resistance). If any
abnormal condition is detected, replace the defective parts.
CARRY OUT 4R CHECKS.
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present between the normal open terminal of the
relay RY1 and the normal open terminal of the relay RY2.
relay RY1 and the normal open terminal of the relay RY2.
Check supply voltage and oven power cord.
2
The rated AC voltage is present to primary side of low voltage transformer.
Low voltage transformer or secondary circuit defective.
Check and repair.
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”.
(J1)
VRS1
RY1
d
a
b
c
R259(W)
9 – 1
R259(W)
Service Manual
CHAPTER 9.
TOUCH CONTROL PANEL ASSEMBLY
[1] OUTLINE OF TOUCH CONTROL PANEL
The touch control section consists of the following units as shown in
the touch control panel circuit.
the touch control panel circuit.
(1) Key Unit (2) Control Unit
The principal functions of these units and their related signals are
explained below.
explained below.
1. Key Unit
The key unit is composed of a matrix, signals generated in the LSI are
sent to the key unit through P22, P23, P24, P25, P26 and P33. When
a key pad is touched, a signal is completed through the key unit and
passed back to the LSI through P50, P51, P52 and P53 to perform the
function that was requested.
sent to the key unit through P22, P23, P24, P25, P26 and P33. When
a key pad is touched, a signal is completed through the key unit and
passed back to the LSI through P50, P51, P52 and P53 to perform the
function that was requested.
2. Control Unit
Control unit consists of LSI, reset circuit, indicator circuit, power
source circuit, relay circuit, buzzer circuit and synchronizing signal cir-
cuit.
source circuit, relay circuit, buzzer circuit and synchronizing signal cir-
cuit.
1) Reset Circuit
This circuit generates a signal which resets the LSI to the initial
state when power is supplied.
state when power is supplied.
2) Indicator Circuit
This circuit consists of 4-digits, 12-segments and 3-common elec-
trodes using a Liquid Crystal Display.
trodes using a Liquid Crystal Display.
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.
AC line voltage. In addition, the synchronizing signal is available in
order to compose a basic standard time in the clock circuit.
4) Relay Circuit
To drive the magnetron, fan motor, turntable motor and light the
oven lamp.
oven lamp.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit audible
sounds (key touch sound and completion sound).
sounds (key touch sound and completion sound).
6) Synchronizing Signal Circuit
The power source synchronizing signal is available in order to com-
pose a basic standard time in the clock circuit. It accompanies a
very small error because it works on commercial frequency.
pose 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.
8) Back Light Circuit
A circuit to drive the back light (Light emitting diodes LD1 - LD4).
[2] DESCRIPTION OF LSI
The I/O signal of the LSI are detailed in the following table.
Symbol
Voltage
Application
VSS
-5V
LSI(IC1)
Pin No.
Signal
I/O
Description
1
P50
IN
Signal coming from touch key.
When either G7 line on key matrix is touched, a corresponding signal out of P22 - P26 and P33 will be input into
P50. When no key is touched, the signal is held at “H” level.
When either G7 line on key matrix is touched, a corresponding signal out of P22 - P26 and P33 will be input into
P50. When no key is touched, the signal is held at “H” level.
2
P51
IN
Signal similar to P50.
When either G8 line on key matrix is touched, a corresponding signal will be input into P51.
When either G8 line on key matrix is touched, a corresponding signal will be input into P51.
3
P52
IN
Signal similar to P50.
When either G9 line on key matrix is touched, a corresponding signal will be input into P52.
When either G9 line on key matrix is touched, a corresponding signal will be input into P52.
4
P53
IN
Signal similar to P50.
When either G10 line on key matrix is touched, a corresponding signal will be input into P53.
When either G10 line on key matrix is touched, a corresponding signal will be input into P53.
5
IC
IN
Connected to VSS.
6
XT1
IN
Connected to VSS.
7
XT2
Terminal not used.
8
VDD
IN
Power source voltage input terminal.
The power source voltage to drive the LSI. Connected to GND.
The power source voltage to drive the LSI. Connected to GND.
9
VSS
IN
Power source voltage input terminal.
The power source voltage to drive the LSI.
The power source voltage to drive the LSI.
10
X1
IN
Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the resistor-capacitor oscillation circuit with respect to X2 termi-
nal.
The internal clock frequency is set by inserting the resistor-capacitor oscillation circuit with respect to X2 termi-
nal.
11
X2
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of X1.
Output to control oscillation input of X1.
12
RESET
IN
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied.
Signal is input to reset the LSI to the initial state when power is applied.
13-15
P00-P02
OUT Terminal not used.
16
P03
OUT Back light circuit (Light emitting diodes) driving signal.
17
CAPH
-
Terminal not used.
18
CAPL
-
Terminal not used.
19-21
VLC0-VLC2
IN
Power source voltage input terminal.
Standard voltage for LCD.
Standard voltage for LCD.
22
COM0
OUT
Common data signal.
Connected to LCD signal C1.
Connected to LCD signal C1.
23
COM1
OUT
Common data signal.
Connected to LCD signal C2.
Connected to LCD signal C2.
R259(W)
9 – 2
24
COM2
OUT
Common data signal.
Connected to LCD signal C3.
Connected to LCD signal C3.
25
COM3
OUT Terminal not used.
26-37
SEG0-SEG11
OUT
Segment data signal.
Connected to LCD.The relation between signals are as follows:
LSI signal (Pin No.) LCD (segment) LSI signal (Pin No.) LCD (segment)
SEG 0 (26) ----------------- S 1 SEG 6 (32) ----------------- S 7
SEG 1 (27) ----------------- S 2 SEG 7 (33) ----------------- S 8
SEG 2 (28) ----------------- S 3 SEG 8 (34) ----------------- S 9
SEG 3 (29) ----------------- S 4 SEG 9 (35) ----------------- S10
SEG 4 (30) ----------------- S 5 SEG 10 (36) ---------------- S11
SEG 5 (31) ----------------- S 6 SEG 11 (37) ---------------- S12
Connected to LCD.The relation between signals are as follows:
LSI signal (Pin No.) LCD (segment) LSI signal (Pin No.) LCD (segment)
SEG 0 (26) ----------------- S 1 SEG 6 (32) ----------------- S 7
SEG 1 (27) ----------------- S 2 SEG 7 (33) ----------------- S 8
SEG 2 (28) ----------------- S 3 SEG 8 (34) ----------------- S 9
SEG 3 (29) ----------------- S 4 SEG 9 (35) ----------------- S10
SEG 4 (30) ----------------- S 5 SEG 10 (36) ---------------- S11
SEG 5 (31) ----------------- S 6 SEG 11 (37) ---------------- S12
38-40
SEG12-SEG14 OUT Terminal not used.
41
P70
OUT
Oven lamp, fan motor and turntable motor driving signal
To turn on and off shut off relay (RY1). The square wave-
form voltage is delivered to the RY1 driving circuit and
RY2 control circuit.
To turn on and off shut off relay (RY1). The square wave-
form voltage is delivered to the RY1 driving circuit and
RY2 control circuit.
42
P71
OUT Terminal not used.
43
P72
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.
44
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.
45-48
AIN5-AIN2
IN
Terminal to change cooking input 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 cooking constant.
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 cooking constant.
49-50
AIN1-AIN0
IN
This is the terminal to detect the voltage of the signal coming from the touch key.
51
AVSS
IN
A/D converter power source voltage.
The power source voltage to drive the A/D converter in the LSI.
The power source voltage to drive the A/D converter in the LSI.
52
P11
IN
To input signal which communicates the door open/close information to LSI.
Door close “H” level signal (0V). Door open “L” level signal (-5V)
Door close “H” level signal (0V). Door open “L” level signal (-5V)
53
P10
OUT Terminal not used.
54
P33
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G1
line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G1
line keys on key matrix is touched.
55
P32
OUT Terminal not used.
56
P31
OUT Terminal not used.
57
INTP0
IN
Signal synchronized with commercial power source frequency.
This is the basic timing for time processing of LSI.
This is the basic timing for time processing of LSI.
58
P26
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G2
line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G2
line keys on key matrix is touched.
59
P25
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G3
line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G3
line keys on key matrix is touched.
60
P24
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G4
line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G4
line keys on key matrix is touched.
61
P23
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G5
line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G5
line keys on key matrix is touched.
62
P22
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G6
line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P50, P51, P52 and P53 terminal while one of G6
line keys on key matrix is touched.
Pin No.
Signal
I/O
Description
20 msec.
During cooking
H : GND
L : -5V
Maximum
output
70% of maximum
output
H : GND
L : -5V
H : GND
L : -5V
ON
ON
OFF
OFF
OFF
24 sec.
8 sec.
20 msec.
H : GND
L : -5V
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