Sharp R-62FBSTM Service Manual ▷ View online
R-61FBSTM/R-62FBSTM - 13
TEST PROCEDURES
CARRY OUT 3D CHECKS.
Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
terminals as described in the table below.
terminals as described in the table below.
Table: Resistance of Motor
Motors
Resistance
Fan motor
Approximately 290
Ω
Turntable motor
Approximately 12 - 15 k
Ω
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
CARRY OUT 4R CHECKS.
LIVE TEST FOR MOTOR WINDING
CAUTION: The following procedure requires the oven to be connected to the supply and should
only be used if the relevant "cold" checks for the motor under test are inconclusive.
1. CARRY OUT 3D CHECKS.
2. Disconnect the leads from the primary of the high voltage transformer. Make sure that the leads
2. Disconnect the leads from the primary of the high voltage transformer. Make sure that the leads
remain isolated from other oven components and chassis (Use insulation tape if necessary.)
3. Connect the voltmeter, set to 250V AC, across the motor terminals. (Refer to the relevant motor test
procedure or pictorial diagram for the correct terminal numbers.)
4. Arrange the meter in a position where it can be read during the test.
(Do not touch the meter, meter leads or oven circuitry while the oven is active.)
5. Close the oven door.
6. Set the power level to 800W and set the relevant timer for about three (3) minutes.
7. Note the reading on the meter and carefully observe the motor under test to see if it is turning.
8. CARRY OUT 3D CHECKS.
9. Remove the test meter leads.
10. Reconnect the leads to the primary of the high voltage transformer.
6. Set the power level to 800W and set the relevant timer for about three (3) minutes.
7. Note the reading on the meter and carefully observe the motor under test to see if it is turning.
8. CARRY OUT 3D CHECKS.
9. Remove the test meter leads.
10. Reconnect the leads to the primary of the high voltage transformer.
If a reading of the line voltage was obtained (step 7) but the motor was not turning then it is faulty and
should be replaced. If the meter indicated that the no supply was present then the winding to the motor
should be O.K.Other circuit checks should be made, i.e. relays,switches.
should be replaced. If the meter indicated that the no supply was present then the winding to the motor
should be O.K.Other circuit checks should be made, i.e. relays,switches.
J
MOTOR WINDING TEST
PROCEDURE
LETTER
COMPONENT TEST
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore,
unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter
and ohmmeter.
In this service manual, the touch control panel assembly is divided into four units, Control Unit, Switch
Unit,LED unit and Relay Unit. Troubleshooting by unit replacement is described according to the
symptoms indicated.
unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter
and ohmmeter.
In this service manual, the touch control panel assembly is divided into four units, Control Unit, Switch
Unit,LED unit and Relay Unit. Troubleshooting by unit replacement is described according to the
symptoms indicated.
1. Switch, NOTE : Check switch unit lead wire harness connection before replacement.
The following symptoms indicate a defective switch unit. Replace the switch unit
a) When touching the keys, a certain key produces no signal at all.
b) When touching a key, two figures or more are displayed.
c) When touching the keys, sometimes a key produces no signal.
a) When touching the keys, a certain key produces no signal at all.
b) When touching a key, two figures or more are displayed.
c) When touching the keys, sometimes a key produces no signal.
2. Control Unit
The following symptoms indicate a defective control unit. Before replacing the control unit, perform
the switch unit test (Procedure L) to determine if control unitis faulty.
the switch unit test (Procedure L) to determine if control unitis faulty.
2-1 In connection with keys.
a) When touching the keys, a certain group of keys do not produce a signal.
b) When touching the keys, no keys produce a signal.
b) When touching the keys, no keys produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some dots do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding dots 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.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding dots 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.
2-3 Other possible problems 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.
b) Clock does not operate properly.
c) Cooking is not possible.
3.
LED Unit
a) No backlight behind display.
b) Dull backlight behind display.
a) No backlight behind display.
b) Dull backlight behind display.
4.
Relay Unit.
a) Grill cooking is not possible.
a) Grill cooking is not possible.
K
TOUCH CONTROL PANEL ASSEMBLY TEST
R-61FBSTM/R-62FBSTM - 14
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
If the display fails to clear when the STOP key is depressed, first verify the lead wire harness is
marking good contact, verify that the stop switch operates properly; that is the contacts are closed
when the door is closed and open when the door is open. If the stop switch is good, disconnect the
lead wire harness that connects the switch unit to the control unit and make sure the stop switch
is closed (either close the door or short the stop switch connecter). Use the switch unit matrix
indicated on the switch unit circuit and place a jumper wire between the pins that correspond to the
STOP key making momentary contact. If the control unit responds by clearing with a beep the
switch unit is faulty and must be replaced. If the control unit does not respond, it is a faulty and must
be replaced. If a specific key does not respond, the above method may be used (after clearing the
control unit) to determine if the control unit or switch unit is at fault.
marking good contact, verify that the stop switch operates properly; that is the contacts are closed
when the door is closed and open when the door is open. If the stop switch is good, disconnect the
lead wire harness that connects the switch unit to the control unit and make sure the stop switch
is closed (either close the door or short the stop switch connecter). Use the switch unit matrix
indicated on the switch unit circuit and place a jumper wire between the pins that correspond to the
STOP key making momentary contact. If the control unit responds by clearing with a beep the
switch unit is faulty and must be replaced. If the control unit does not respond, it is a faulty and must
be replaced. If a specific key does not respond, the above method may be used (after clearing the
control unit) to determine if the control unit or switch unit is at fault.
L
SWITCH UNIT TEST
Remove the outer case and check voltage between Pin No. 1 and Pin No. 3 of the 3 pin connector (A)
on the control unit with an A.C. voltmeter.
The meter should indicate rated voltage, if not check oven circuit.
on the control unit with an A.C. voltmeter.
The meter should indicate rated voltage, if not check oven circuit.
M
RELAY TEST
RY1, RY2, RY3 and RY4 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, dual or
grill 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, dual or
grill 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
RY2
Approx. 12.0V D.C.
Heating element
RY3
Approx. 12.0V D.C.
High voltage transformer
RY4
Approx. 12.0V D.C.
Fan motor
CARRY OUT 4R CHECKS.
(J1
1)
(J10)
13
12
10
11
SW2
ENCODER
A
B
C
RSW1
6
7
8
+1MIN
SW4
(J13)
(J12)
(J15)
(J14)
(J17)
(J16)
STOP
1.
2.
SW3
9
2
5
4
3
1
Switch unit
14
AUTOMATIC
SW1
4.7KF
24KF
3.
+
N
GRILL HEATING ELEMENT TEST
CARRY OUT 3D CHECKS.
Before carrying out the following tests make sure the heating element is cooled completely.
1. Resistance of heating element.
1. Resistance of heating element.
Disconnect the wire leads to the heating element to be tested. Using ohmmeter with low resistance
range. Check the resistance across the terminals of the heating element as described in the
following table.
range. Check the resistance across the terminals of the heating element as described in the
following table.
Table: Resistance of heating element
Parts name
Resistance
Grill heating element (top)
Approximately 76
Ω
2. Insulation resistance.
Disconnect the wire leads to the heating element to be tested. Check the insulation resistance
between the element terminal and cavity using a 500V - 100M
between the element terminal and cavity using a 500V - 100M
Ω
insulation tester. The insulation
resistance should be more than 10 M
Ω
in the cold element.
If the results of above test 1 and/or 2 are out of above specifications, the heating element is probably
faulty and should be replaced.
CARRY OUT 4R CHECKS.
faulty and should be replaced.
CARRY OUT 4R CHECKS.
R-61FBSTM/R-62FBSTM - 15
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
O
PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED
WIRING BOARD (PWB) IS OPEN
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, indicator does not light up.
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 BEFORE REPAIR
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present between
Check supply voltage and oven power cord.
Pin No. 1 of the 3 pin connector (A)
2
.The rated AC voltage is not present at primary Low voltage transformer or secondary circuit defective.
side of low voltage transformer.
side of low voltage transformer.
check and repair.
3
Pattern at "a" is broken.
*Insert jumper wire J1 and solder.
(CARRY OUT 3D CHECKS BEFORE REPAIR)
(CARRY OUT 3D CHECKS BEFORE REPAIR)
4
Pattern at "a" and "b" are broken.
*Insert the coil RCILF2003YAZZ between "c" and "d
(CARRY OUT 3D CHECKS BEFORE REPAIR)
CARRY OUT 4R CHECKS
NOTE: *At the time of making these repairs, make
a visual inspection of the varistor. Check
for burned damage. If any abnormal condi-
tion is detected, replace the defective parts.
for burned damage. If any abnormal condi-
tion is detected, replace the defective parts.
CNA
VRS1
D24
1
5
RY4
J1
c
a
d
b
1
The touch control section consists of the following
units as shown in the touch control panel circuit.
(1) Switch Unit
units as shown in the touch control panel circuit.
(1) Switch Unit
(3) LED Unit
(2) Control Unit
(4) Relay Unit
The principal functions of these units and the signals
communicated among them are explained below.
communicated among them are explained below.
Switch Unit
The switch unit is composed of a matrix,signals
generated in the LSI are sent to the swit ch unit
through P22,P23 and P24.
When a switch button is touched, a signal is com-
pleted through the switch unit and passed back to the
LSI through P50 and P51 to perform the function that
was requested.
The switch unit is composed of a matrix,signals
generated in the LSI are sent to the swit ch unit
through P22,P23 and P24.
When a switch button is touched, a signal is com-
pleted through the switch unit and passed back to the
LSI through P50 and P51 to perform the function that
was requested.
Control Unit
Control unit consists of LSI, power source circuit,
relay circuit, back light circuit, synchronizing signal
circuit, reset circuit, buzzer circuit, and indicator cir-
cuit.
Control unit consists of LSI, power source circuit,
relay circuit, back light circuit, synchronizing signal
circuit, reset circuit, buzzer circuit, and indicator cir-
cuit.
1) LSI
This LSI controls the tact switch strobe signal,
relay driving signal, for oven function and indicator
signal.
relay driving signal, for oven function and indicator
signal.
2) Power Source Circuit
This circuit generates voltage necessary in the
control unit.
control unit.
Symbol
Voltage
Application
VC
-5.0V
LSI(IC1)
3) Synchronizing Signal Circuit
The power source synchronizing signal is avail-
able in order to compose a basic standard time in
able in order to compose a basic standard time in
CONTROL PANEL ASSEMBLY
OUTLINE OF CONTROL PANEL
the clock circuit. It accompanies a very small error because
it works on commercial frequency.
it works on commercial frequency.
4) ACL Circuit
A circuit to generate a signals which resets the LSI to the
initial state when power is supplied.
initial state when power is supplied.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
audible sounds (tact switch touch sound and completion
sound).
audible sounds (tact switch touch sound and completion
sound).
6) Stop Switch
A switch to "tell" the LSI if the door is open or closed.
7) Relay Circuit
To drive the magnetron, fan motor, turntable motor, heating
element, and light the oven lamp.
element, and light the oven lamp.
8) Indicator Circuit
This circuit consists of 4-digits, 12-segments and 3-com-
mon electrodes using a Liquid Crystal Display.
mon electrodes using a Liquid Crystal Display.
9) Encoder
The encoder converts the signal generated by LSI into the
pulse signal, and the pulse signal is returned to the LSI
pulse signal, and the pulse signal is returned to the LSI
10) Back Light Circuit
A circuit to drive the back light (Light emitting diodes LD1-
LD3).
LD3).
LED Unit
A circuit consisting of three light emitting diodes (LD1-
LD3)which are driven by the control unit and provide the
backlight for the display.
A circuit consisting of three light emitting diodes (LD1-
LD3)which are driven by the control unit and provide the
backlight for the display.
Relay Unit
A circuit consisting of a relay (RY2) and a doide(D23) which
are driven by the control unit and provide the supply voltage
to the heating element.
A circuit consisting of a relay (RY2) and a doide(D23) which
are driven by the control unit and provide the supply voltage
to the heating element.
R-61FBSTM/R-62FBSTM - 16
DESCRIPTION OF LSI
LSI(IXA216DRZZ)
The I/O signal
The I/O signal
of the LS
I(IXA216DRZZ) are detailed in the following table.
Pin No.
Signal
I/O
Description
1
P50
IN
Signal coming from tact switch.
When tact switch SW4 is touched, a signal out of P24 will be input into P50. When no tact
switch is touched, the signal is held at “H” level.
When tact switch SW4 is touched, a signal out of P24 will be input into P50. When no tact
switch is touched, the signal is held at “H” level.
2
P51
IN
Signal coming from tact switch.
When either tact switches SW1, SW2 and SW3 is touched, a corresponding signal out of
P22, P23 and P24 will be input into P51. When no tact switch is touched, the signal is held
at “H” level.
When either tact switches SW1, SW2 and SW3 is touched, a corresponding signal out of
P22, P23 and P24 will be input into P51. When no tact switch is touched, the signal is held
at “H” level.
3
P52
IN
Terminal not used.
4
P53
OUT
Terminal not used.
5
VPP
_
Connected to VSS through the resistor.
6
XT1
IN
Connected to VSS.
7
XT2
_
Terminal not used.
8
VDD
IN
Power source voltage input terminal.
The power souce voltage to drive the LSI. Connected to GND.
The power souce voltage to drive the LSI. Connected to GND.
9
VSS
IN
Power source voltage input terminal.
The power souce voltage to drive the LSI.
The power souce voltage to drive the LSI.
10
X1
IN
Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to X2 terminal.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to X2 terminal.
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.
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.
Connected to LCD.
The relation between signals are as follows:
LSI signal (Pin No.)
LSI signal (Pin No.)
LCD (segment)
LSI signal (Pin No.)
LCD (segment)
SEG 0 (26) ................................. S1
SSEG 6 (32) ...................................... S7
SEG 1 (27) ................................. S2
SEG 7 (33) ....................................... S8
SEG 2 (28) ................................. S3
SEG 8 (34) ....................................... S9
SEG 3 (29) ................................. S4
SEG 9 (35) ..................................... S10
SEG 4 (30) ................................. S5
SEG 10 (36) ..................................... S11
SEG 5 (31) ................................. S6
SEG 11 (37) ..................................... S12
38-40
SEG12-SEG14
OUT
Terminal not used.
41
P70
OUT
Oven lamp 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.
square waveform voltage is delivered to the
RY1 driving circuit.
20 msec.
During cooking
H : GND
L : -5V
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