Sharp QT-CD250 (serv.man6) Service Manual ▷ View online
QT-CD250H/W
– 21 –
• Laser failure.
Yes
No
Check the laser come on when pattern cut between pin 8 (SEL) of
IC801 and pin 74 (SEL) of IC802.
IC801 and pin 74 (SEL) of IC802.
Yes
No
Check the peripheral parts of IC801 and Q801. If it is normal, the
optical pickup is faulty.
optical pickup is faulty.
Check BI801/CNS801. If it is normal, the optical pickup is
faulty.
faulty.
Is approx. 1.8V applied to the collector of Q801.
• Focus failure.
Does the optical pickup move up and down when the disc is
removed?
removed?
Is the following waveform ouput at the pin 62 (FEI) of IC802
when the disc is set?
when the disc is set?
Is the waveform shown above input at the pin 63 (SBAD) of
IC802?
IC802?
Yes
Yes
No
No
The optical pickup is faulty.
Check as stated in item "FOCUS SERVO SAWTOOTH WAVE
FAILURE".
FAILURE".
Yes
Check the periphery of IC801 and BI801/CNS801. Is it normal?
No
Check the pattern between pin 13 of IC801 and pin 63 of IC802.
Check the periphery of IC801 and BI801/CNS801.
Check the periphery of IC801 and BI801/CNS801.
IC801 is faulty.
Yes
Is +7.5V applied to the Collector of Q206 ?
Is +5V applied to the collector of Q204 and Q806 ?
Yes
No
No
Check the PWB pattern of Q206.
Check the PWB Patten of IC204 and Q806.
Is +5V applied to the pin 75 (VDD) and pin 96 (MVDD) of
IC802 ?
IC802 ?
Is +5V applied to the pin 1 (VCC) of IC801 ?
Yes
No
No
Check the PWB pattern between collector of Q806 and pin 75 of
IC802, and emiter of Q806 and Q804 and pin 96 of IC802.
IC802, and emiter of Q806 and Q804 and pin 96 of IC802.
Check the PWB pattern between collector of Q204 and pin 1 of
IC801.
IC801.
pin 62
(FEI)
pin 86
(FOO)
pin 63
(SBAD)
Yes
Yes
Is +0V applied to the pin 74 (SEL) of IC802 ?
QT-CD250H/W
– 22 –
• Focus servo sawtooth wave failure.
Is +7.5V applied to the pins 1 and 30 (VCC) of IC803 ?
Is sawtooh wave output to the pin 66 (FOO) of IC802 ?
IC802 is faulty.
No
Yes
Yes
Is sawtooth wave obtained between pins 20 and 21 of IC803 ?
No
Check the PWB pattern of IC803.
Check the PWB pattern of IC803.
No
Is sawtooth wave obtained between pins 3 and 4 of BI801/
CNS801 ? (as shown above)
CNS801 ? (as shown above)
Yes
Check the PWB pattern between BI801/CNS801 and IC803.
No
BI801/CNS801 connection failure or optical pickup failure.
Yes
• Spindle motor clv servo failure.
Is above wave obtained between pins 5 and 6 of IC803 ?
Is following wave output to the pin 72 (DMO) of IC802 when
the Function is changed to "PLAY" from "STOP" ?
the Function is changed to "PLAY" from "STOP" ?
No
Yes
Check the procedure in "HF ERROR".
If OK. IC802 is faulty.
If OK. IC802 is faulty.
Check the PWB pattern between pin 72 (DMO) of IC802 and pins
5 and 6 of IC803. If OK. IC803 is faulty.
5 and 6 of IC803. If OK. IC803 is faulty.
No
Is above wave obtained between pins 5 and 6 of BI803/
CNS803 ?
CNS803 ?
Yes
Check the PWB pattern between BI803/CNS803 and IC803.
No
BI803/CNS803 connection failure or optical pickup failure.
Yes
DMO
1.5~2.5sec
1.5~2.5sec
QT-CD250H/W
– 23 –
• Sled motor operation failure.
Yes
Yes
Is following sled feed signal output the pin 71 (FMO) of IC802
when FF/REW key is pressed after the CD TEST MODE is
seted?
when FF/REW key is pressed after the CD TEST MODE is
seted?
Is sled feed signal output the pins 10 and 11 of IC803?
Is sled feed voltage applied between both terminals of sled
motor?
motor?
No
Check the peripheral parts of IC803. If OK, IC803 is faulty.
No
IC802 is faulty.
Check the BI803/CNS803.
No
Yes
Check the CD mechanism (periphery of sled motor).
If the sled motor does not run when DC2.0V is applied to
both terminals of sled motor, the sled motor is faulty.
If the sled motor does not run when DC2.0V is applied to
both terminals of sled motor, the sled motor is faulty.
• Sled servo failure.
Yes
Is following sled signal output the pin 71 (FMO) of IC802
during playback?
during playback?
Normal.
No
IC802 is faulty.
• Track search failure
Does the sled motor run in FF/REW state when the CD
TEST MODE is set?
TEST MODE is set?
Is the following wave output to the pin 67 (TRO) of IC802
during track search in normal playback?
during track search in normal playback?
Is the following wave output to the pins 12 (TEO) of IC801
during track search in normal playback?
during track search in normal playback?
Yes
Yes
No
Check as stated in item "SLED MOTOR OPERATION FAILURE".
No
IC802 failure.
No
Check the PWB pattern between pin 67 (TRO) of IC802 and pin
28 of IC803.
Check the PWB pattern between pins 25 and 26 of IC803 and
Optical pickup.
If OK. Optical pickup failure.
28 of IC803.
Check the PWB pattern between pins 25 and 26 of IC803 and
Optical pickup.
If OK. Optical pickup failure.
Yes
Is the above wave output to the pins 64 (TEI) and 65 (TEZI)
of IC802 during track serch in normal playback?
of IC802 during track serch in normal playback?
No
Check the PWB pattern between pin 12 (TEO) of IC801 and pins 64
(TEI) and 65 (TEZI) of IC802. If OK. IC801 failure.
(TEI) and 65 (TEZI) of IC802. If OK. IC801 failure.
Normal.
Yes
Yes
Is following sled feed signal input the pins 12 and 13 of IC803
when FF/REW key is pressed after the CD TEST MODE is
seted?
when FF/REW key is pressed after the CD TEST MODE is
seted?
Check the PWB pattern between pin 71 of IC802 and pins 12 and
13 of IC803.
13 of IC803.
No
Is the following wave output to the pin 60 (RFZI) and 61
(RFRP) of IC802 during track search in normal playback?
(RFRP) of IC802 during track search in normal playback?
No
Check the PWB pattern between pin 22 (RFO) and 18 (RFIS), 17
(RFRP) of IC801 and pins 60 and 61 of IC802. If OK. IC801 failure.
(RFRP) of IC801 and pins 60 and 61 of IC802. If OK. IC801 failure.
Yes
TRO
TEO
TEI
TEZI
FF
REW
FMO
FMO
RFRP
RFZI
FF
REW
SL
±
QT-CD250H/W
– 24 –
IC51 VHiLC72121/-1: Electronic Tuning (LC72121) (1/2)
1
Xtal
XIN
Output
Crystal oscillator connection.(4.5 MHz/7.2 MHz)
2
Ground
VSSX
Output
Ground terminal for the crystal oscillation circuit system of LC72121.
3
Chip enable
CE
Output
High level when inputting serial data (DI) to LC72121 or sending
serial data (DO).
serial data (DO).
4
Input data
DI
Input
Input terminal for serial data that is transferred from the controller to
LC72121.
LC72121.
5
Clock
CL
Output
Clock that synchronizes data when inputting serial data (DI) to
LC72121 or sending serial data (DO).
LC72121 or sending serial data (DO).
6
Output data
DO
Output
Output terminal that sends data from LC72121 to the controller. The
output data is defined by serial data DOC0-DOC2.
output data is defined by serial data DOC0-DOC2.
7*
Output port
BO1
Output
Output dedicated terminal.
Output state is defined by the serial data BO1-BO4.
Data 0: Open
Data 1: L
Time base signal (8 Hz) output is possible from BO1 terminal.
(When setting serial data TBC = 1.)
Output state is defined by the serial data BO1-BO4.
Data 0: Open
Data 1: L
Time base signal (8 Hz) output is possible from BO1 terminal.
(When setting serial data TBC = 1.)
8-10
Output port
BO2-BO4
Output
Output dedicated terminal.
Output state is defined by the serial data BO1-BO4.
Data 0: Open
Data 1: L
Time base signal (8 Hz) output is possible from BO1 terminal.
(When setting serial data TBC = 1.)
Output state is defined by the serial data BO1-BO4.
Data 0: Open
Data 1: L
Time base signal (8 Hz) output is possible from BO1 terminal.
(When setting serial data TBC = 1.)
11
Input/output port
IO1
Input/Output Terminal for both input and output.
Input and output are defined by serial data IDC1 and IOC2.
Data 0: Input port
Data 1: Output port
When specified as the input port.
The input terminal state is transferred from the DO terminal to the
controller.
Input state "L": Data -> 0
Input state "H": Data -> 1
When specified as the output port.
Output state is defined by the serial data IO1 and IO2.
Data 0: Open
Data 1: L
When turning on the power or resetting, the terminal becomes the
input port.
Data 0: Input port
Data 1: Output port
When specified as the input port.
The input terminal state is transferred from the DO terminal to the
controller.
Input state "L": Data -> 0
Input state "H": Data -> 1
When specified as the output port.
Output state is defined by the serial data IO1 and IO2.
Data 0: Open
Data 1: L
When turning on the power or resetting, the terminal becomes the
input port.
12
IF counter
IF IN
Input
Input frequency is 0.4-12 MHz.
Signal is transferred to the IF counter directly.
The result is sent from M5B of the IF counter through DO.
4 measuring times: 4, 8, 32, and 64 ms
Signal is transferred to the IF counter directly.
The result is sent from M5B of the IF counter through DO.
4 measuring times: 4, 8, 32, and 64 ms
13
Input/output port
IO2
Input/Output Terminal for both input and output.
Input and output are defined by serial data IDC1 and IOC2.
Data 0: Input port
Data 1: Output port
When specified as the input port.
The input terminal state is transferred from the DO terminal to the
controller.
Input state "L": Data -> 0
Input state "H": Data -> 1
When specified as the output port.
Output state is defined by the serial data IO1 and IO2.
Data 0: Open
Data 1: L
When turning on the power or resetting, the terminal becomes the
input port.
Data 0: Input port
Data 1: Output port
When specified as the input port.
The input terminal state is transferred from the DO terminal to the
controller.
Input state "L": Data -> 0
Input state "H": Data -> 1
When specified as the output port.
Output state is defined by the serial data IO1 and IO2.
Data 0: Open
Data 1: L
When turning on the power or resetting, the terminal becomes the
input port.
14
Ground
VSSD
—
Ground terminal for the digital system other than VSSA and VSSX of
LC72121.
LC72121.
Port Name
Terminal
Name
Pin No.
Input/Output
Function
FUNCTION TABLE OF IC
In this unit, the terminal with asterisk mark (*) is (open) terminal which is not connected to the outside.
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