Sharp QT-CD141, QT-CD161 User Manual

Illustration: QT-CD161

QT-CD161/141

SERVICE MANUAL

No. S5929QTCD161/

QT-CD161(S)
QT-CD141(BK)

• In the interests of user-safety the set should be restored to its
original condition and only parts identical to those specified should
be used.

CONTENTS

Page

IMPORTANT SERVICE NOTES (FOR U.S.A. ONLY)....................................................................................................... 2

SPECIFICATIONS ............................................................................................................................................................. 2

NAMES OF PARTS ........................................................................................................................................................... 3

REMOTE CONTROL ..........................................................................................................................................................3

DISASSEMBLY.................................................................................................................................................................. 4

REMOVING AND REINSTALLING THE MAIN PARTS..................................................................................................... 5

ADJUSTMENT ................................................................................................................................................................... 6

NOTES ON SCHEMATIC DIAGRAM ................................................................................................................................ 9

TYPES OF TRANSISTOR ................................................................................................................................................. 9

WAVEFORMS OF CD CIRCUIT...................................................................................................................................... 10

BLOCK DIAGRAM ........................................................................................................................................................... 11

SCHEMATIC DIAGRAM / WIRING SIDE OF P.W.BOARD............................................................................................. 14

TROUBLESHOOTING (CD SECTION) ........................................................................................................................... 23

FUNCTION TABLE OF IC................................................................................................................................................ 27

PARTS GUIDE/EXPLODED VIEW
PACKING OF THE SET (FOR U.S.A. ONLY)

DIFFERENCE BETWEEN QT-CD161 AND QT-CD141

SECTION

REMOTE CONTROL
HEADPHONE SOCKET

QT-CD161

QT-CD141

SHARP CORPORATION

– 1 –

This document has been published to be used
for after sales service only.
The contents are subject to change without notice.

QT-CD161/141

g

FOR A COMPLETE DESCRIPTION OF THE OPERATION OF THIS UNIT, PLEASE REFER
TO THE OPERATION MANUAL.

IMPORTANT SERVICE NOTES (FOR U.S.A. ONLY)

BEFORE RETURNING THE AUDIO PRODUCT

(Fire & Shock Hazard)
Before returning the audio product to the user, perform the
following safety checks.

1. Inspect all lead dress to make certain that leads are not
pinched or that hardware is not lodged between the chassis
and other metal parts in the audio product.

2. Inspect all protective devices such as insulating materials,

cabinet, terminal board, adjustment and compartment covers
or shields, mechanical insulators etc.

3. To be sure that no shock hazard exists, check for leakage

current in the following manner.
* Plug the AC line cord directly into a 120 volt AC outlet.
* Using two clip leads, connect a 1.5k ohm, 10 watt resistor

paralleled by a 0.15µF capacitor in series with all exposed
metal cabinet parts and a known earth ground, such as
conduit or electrical ground connected to earth ground.

* Use a VTVM or VOM with 1000 ohm per volt, or higher,

sensitivity to measure the AC voltage drop across the
resistor (See diagram).

* Connect the resistor connection to all exposed metal parts

having a return path to the chassis (antenna, metal cabinet,
screw heads, knobs and control shafts, escutcheon, etc.)
and measure the AC voltage drop across the resistor.

VTVM

AC SCALE

1.5k ohms
10W

0.15 µ F

TO EXPOSED
METAL PARTS

All check must be repeated with the AC line cord plug connection
reversed.
Any reading of 0.3 volt RMS (this corresponds to 0.2 milliamp.
AC.) or more is excessive and indicates a potential shock
hazard which must be corrected before returning the audio
product to the owner.

TEST PROBE

CONNECT TO
KNOWN EARTH
GROUND

SPECIFICATIONS

● General
Power source: AC 120 V, 60 Hz

DC 12 V [ "D" size (UM/SUM-1,
R20 or HP-2) battery × 8]
DC 3 V [ "AA" size (UM/SUM-3,
R6 or HP-7) battery × 2 for tuner
memory]

Power
consumption:
Output power: FTC; 2.0 W min. RMS per channel

Speakers: 4" (10 cm) full-range speaker x 2
Output
terminals:
Dimensions: Width; 18-15/16" (480 mm)

Weight: 7.1 lbs. (3.2 kg) without batteries

● Radio
Frequency

e:

ran

Stand-by; 1.5 W
Power on; 20 W

into 8 ohms from 150 Hz to 20
kHz, with no more than 10 % total
harmonic distortion.
RMS; 2.3 W/CH
(DC operation, 10 % T.H.D.)

Headphones; 16-50 ohms
(recommended; 32 ohms)

Height; 6-1/16" (153 mm)
Depth; 10" (254 mm)

FM; 87.5 - 108 MHz
AM; 530 - 1,720 kHz

● Tape recorder
Frequency

response: 50 - 14,000 Hz (Normal tape)
Signal/noise
ratio: 50 dB
Wow and
flutter: 0.25 % (WRMS)
Motor: DC 12 V electric governor
Bias system: AC bias
Erase
system: Magnet erase

● Compact disc player
Type: Compact disc

Signal
readout:

Non-contact, 3-beam semi-con­ductor laser pickup

Audio
channels: 2
Quantization: 16-bit linear quantization
Filter: 4-times oversampling digital filter
D/A
converter: 1-bit D/A converter
Wow and
flutter:

Specifications for this model are subject to change without
prior notice.

Unmeasurable
(less than 0.001% W. peak)

– 2 –

NAMES OF PARTS

QT-CD161/141

1. Cassette Compartment

2. CD Compartment

3. (TAPE) Record Button:

4. (TAPE) Play Button:

5. (TAPE) Rewind Button:

6. (TAPE) Fast Forward Button:

7. (TAPE) Stop/Eject Button:

8. (TAPE) Pause Button:

9. Band/Pause:

10. Tuner Memory

11. Volume

12. Power, On/Function Switch

13. Extra Bass Button: X-BASS

14. (CD) Track Down: /Review Button:

15. (CD) Track Up: /Cue Button:

16. (TUNER)Tuning: /(CD) Stop Button:

17. (TUNER) Tuning: /(CD) Play/Repeat Button:

18. FM Telescopic Rod Aerial

19. Headphone Socket (QT-CD161 Only)

20. Battery Compartment

21. AC Power Input Socket

/

10

16

12

334455678

1

2

9

15

171113

14

1918

Remote control (QT-CD161 ONLY)

1. (TUNER) Tuning: /(CD) Play/Repeat Button:

2. (CD) Track Down: /Review Button:

3. Band/Pause:

4. (CD) Track Up: /Cue Button:

5. (TUNER)Tuning: /(CD) Stop Button:

REMOTE CONTROL (QT-CD161 ONLY)

Notes concerning use:

● Replace the batteries if the operating distance is
reduced or if the operation becomes erratic.

● Periodically clean the transmitter LED on the
remote control and the sensor on the main unit
with a soft cloth.

● Exposing the sensor on the main unit to strong
light may interfere with operation. Change the
lighting or the direction of the unit.

● Keep the remote control away from moisture,
excessive heat, shock, and vibrations.

20 21

1

2

Sensor Remote

15

15

8" - 20'
(0.2 m - 6 m)

0,2 m - 6 m

– 3 –

QT-CD161/141

(B2)x2
ø3x10mm

(A2)x1

(B3)x1

Front Cabinet

Top Cabinet

(B1)x1

Main PWB

(B2)x1

ø3x10mm

DISASSEMBLY

Caution on Disassembly

Follow the below-mentioned notes when disassembling the
unit and reassembling it, to keep it safe and ensure excellent
performance:

1. Take cassette tape and compact disc out of the unit.

2. Be sure to remove the power supply plug from the wall
outlet before starting to disassemble the unit.

3. Take off nylon bands or wire holders where they need to
be removed when disassembling the unit. After servicing
the unit, be sure to rearrange the leads where they were
before disassembling.

4. Take sufficient care on static electricity of integrated
circuits and other circuits when servicing.

STEP REMOVAL PROCEDURE FIGURE

1 Rear Cabinet 1. Screw ................. (A1) x10 4-1

2. Socket .................. (A2) x1 4-2

2 Top Cabinet 1. Knob..................... (B1) x1 4-2

(with CD Mechanism/

Tape Mechanism/ 3. Socket .................. (B3) x1

Main PWB)

3 Main PWB/ 1. Screw ................... (C1) x9 4-3,5-1

Switch PWB/ 2. Socket .................. (C2) x4 4-3,5-1

Headphones PWB 3. Soldering .............. (C3) x3 4-3

(QT-CD161 Only)

4 Tape Mechanism 1. Screw ................... (E1) x4 5-1

5 CD Mechanism 1. Screw ................... (F1) x3 5-1

6 Terminal PWB 1. Screw ...................(G1) x5 5-2

7 Battery PWB 1. Hook.....................(H1) x2 5-3

2. Screw ................... (B2) x3

2. Hook.....................(G2) x1

Figure 4-2

(A1)x6
ø3x20mm

(A1)x1
ø3x12mm

(A1)x3
ø3x12mm

Figure 4-1

Front Cabinet

Rear Cabinet

(C1)x6
ø3x10mm

(C1)x2
ø3x10mm

Headphones
PWB

(C3)x3

(C2)x1

Switch
PWB

Main PWB

(C2)x2

Top Cabinet

Figure 4-3

– 4 –

(E1)x4

Driver

Push

(G2)x1

ø3x10mm

QT-CD161/141

(F1)x3
ø2.5x10mm

Tape
Mechanism

Top Cabinet

Figure 5-1

CD Mechanism

(C2)x1

(C1)x1
ø2.5x8mm

Rear Cabinet

Pull

(H1)x1

(G1)x2
ø3x10mm

(G1)x1
ø3x10mm

Terminal PWB

(G1)x2
ø3x10mm

Figure 5-2

Rear Cabinet

(H1)x1

REMOVING AND REINSTALLING THE MAIN PARTS

CD MECHANISM SECTION

Perform steps 1, 2, 3 and 5 of the disassembly method to
remove the CD mechanism.

How to remove the pickup (See Fig. 5-4.)

1. Remove the screws (A1) x 2 pcs., to remove the shaft (A2)
x1 pcs.

2. Remove the stop washer (A3) x1 pcs., to remove the gear
(A4) x 1 pcs.

3. Remove the pickup.

Shaft
(A2) x1

Pickup

Battery PWB

Figure 5-3

Pull

(A1) x2
ø2.6 x6mm

CD
Mechanism

Stop
Washer
(A3) x1

Gear
(A4) x1

Figure 5-4

– 5 –

QT-CD161/141

Pin 13 of IC2 Pin 21 of IC2

D

G

S

10 kohm

TO FREQUENCY
COUNTER

FET : 2SK19 or 2SK54

MECHANISM SECTION

• Driving Force Check

Torque Meter

PLAY: TW-2412 Over 120 g

• Torque Check

Torque Meter

Play: TW-2111 25 to 65 g.cm
Fast Forward: TW-2231 60 to 130 g.cm
Rewind: TW-2231 60 to 130 g.cm

• Head Azimuth

Torque Meter

MTT-114 Output: Speaker Terminal

• Tape Speed

Test

Tape

MTT-111 In motor 3,000 ± 90 Hz Output: Speaker

Adjusting

Point

TAPE SECTION

Position of each switch or control

Volume control Max
Function switch Tape/Power Off
X-BASS On

• Bias Oscillation

Adjustment Point

L301 82 kHz ± 6 kHz Pin 2 of CNP201

• Playback Amplifier Sensitivity Check

Test Tape

MTT-118 1.8 V ± 3 dB Speaker Terminal

AM TRACKING

fL fH

L3

AM BAR

ANTENNA

FM RF

Specified Value

Specified Value

Specified Value

(CNP201 Load resistance: 8 ohms)

Specified

Specified Value

– 6 kHz

Specified Value

TC1

TP1

R7

FM IF

L1

T1

1

IC1

Value

Instrument Connection

(Load resistance: 8 ohms)

FM ROD ANTENNA

AM BAND

COVERAGE

L4

FM DET.

L2

FM BAND

COVERAGE

Instrument

Connection

Teaminal
(CNP201 Load
resistance: 8 ohms)

Instrument

Connection

R26

T2

19

17

21

IC2

1

T3

AM IF

Figure 6-2 ADJUSTMENT POINTS

ADJUSTMENT

TUNER SECTION

fL: Low-range frequency
fH: High-renge frequency

• FM RF

Signal generator: 1 kHz, 75 kHz dev., FM modulated

Test Stage

Band — 87.5 MHz (fL): L2 *1
Coverage 2.0 ± 0.1 V

RF 90.0 MHz 90.0 MHz L1 *2

*1. Input: Antenna, Output: TP1
*2. Input: Antenna, Output: Speaker Terminal

• Detection

Signal generator: 10.7 MHz, FM sweep generator

IF 10.7 MHz 98.00 MHz T1(Turn Input: Pin 1 of

• AM IF/RF

Signal generator: 400 Hz, 30%, AM modulated

Test Stage

IF 450 kHz 1,720 kHz T3 *1

Band — 530 kHz (fL): L4 *3

Coverage
Tracking 600 kHz 600 kHz (fL): L3 *2

*1. Input: Antenna, Output: Pin19 of IC2
*2. Input: Antenna, Output: Speaker Terminal
*3. Input: Input is not connected, Output: TP1

• VCO Frequency

VR1 76 kHz ± 200 Hz Pin 13, pin 21 and

Note:

After preparing the test circuit shown in Fig. 6-1, connect the
Pin 13, Pin 21 and ground of the IC2 with the test circuit, and
measure the value. At this time, apply a standard unmodulated

MAIN PWB

TP2

VR1

13

VCO

signal input and adjust the VCO.

– 6 –

Frequency

(10~30 dB)

Test

Stage

Adjusting Point

Frequency

Frequency Frequency

1,400 kHz 1,400 kHz (fH):TC1

Frequency

Display

Frequency

Display

Display

Specified

Value

Setting/

Adjusting

Parts

Setting/

Adjusting

Parts

the core of IC1
T1 fully Output: TP2
counter­clockwise.

Setting/

Adjusting

Parts

1.4 ± 0.05 V

ground of IC2

Figure 6-1 VCO FREQUENCY TEST CIRCUIT

Instrument

Connection

Instrument

Connection

Instrument

Connection

Instrument

Connection

QT-CD161/141

TURNING ON THE TEST MODE

The types of test mode for this microcomputer and specific test mode turning-on procedure are as follows. Only the unit key is used.
The remote control key is not valid. The power must be turned on while two keys are held down.
(1) CD test mode function

The power is turned while the (PRESET ) and STOP (TUNING ) keys are held down.

(2) Tuner test mode function

The power is turned on while the (PRESET ) and PAUSE (BAND) keys are held down.

(3) LCD test mode function

The power is turned on while the (PRESET ) and MEMORY keys are held down.

CD TEST MODE

When the CD test mode is turned on, the CD pickup is moved to the innermost periphery, and the following indication appears.
The operation of CD test mode is as follows.

Indication

(1) The CD pickup is moved with the unit UP key and DOWN key.

UP key: The pickup is slid to the outer periphery.
DOWN key: The pickup is slid to the inner periphery. However, when it reaches the innermost periphery, it does not move further
inward.

(2) When the PLAY key is pressed in stop state, the laser diode turns on if CD lid is closed.
Indication

(3) When the PLAY key is pressed in laser ON state, playback is started from the current position of pickup.
Indication

The current playback track No. and time are indicated.

(4) When the STOP key is pressed during playback, the laser goes out and playback is stopped, and the process returns to step

(1). (The pickup position does not change.)

(5) When the MEMORY key is pressed during playback, tracking servo ON/OFF is performed. (Even if the playback is stopped

in servo OFF state, the servo is turned on when the playback is restored.)

Indication

Others

While the CD lid is open (LID-SW = "H"), the test mode is turned on but the operations of step (2) and subsequent steps are not
performed. The operation of step (1) is performed.

The current pickup position and time are indicated. (When the
pickup is moved with the UP/DOWN key, the time at that point
is indicated.)

Contents of error display

Error display

Er 01
Er 02

when TOC information cannot be read normally.
When a PU-IN SW detection error occurs.

Contents of an error

TUNER TEST MODE

The tuner test mode is intended to store the measurement frequency for adjustment and inspection in the preset memory CH
without frequency adjustment in the case of tuner adjustment in the production line.
When the power is turned on while the PRESET (DOWN) key and BAND (PAUSE) key are held down together, the frequency
for adjustment measurement of destination (specified according to AREA terminal) is preset-stored in the preset memory CH. (The
frequency to be preset-stored for specific destination is as shown in the next page.)

– 7 –

QT-CD161/141

In the tuner test mode the band is FM, and the mode is FM STEREO in case of start-up.
As with the ordinary mode, when the PRESET key is pressed for 1ch of preset memory CH, maximum CH is set. When the

PRESET key is pressed for maximum CH of preset memory CH, 1ch is set.
The BAND key is valid. As in the ordinary mode, the band/FM MONO/STEREO mode can be switched.
To exit from the tuner test mode, turn off the power to the microcomputer.
Indication

Preset frequencies for various destinations (random preset memory)

BAND (CH) U.S.A. EUROPE GENERAL 1 GENERAL 2

1 FM 87.5M FM 87.50M FM 87.50M FM 87.5M
2 FM 108.0M FM 108.00M FM 108.00M FM 108.0M
3 FM 98.0M FM 98.00M FM 98.00M FM 98.0M
4 FM 90.0M FM 90.00M FM 90.00M FM 90.0M
5 FM 106.0M FM 106.00M FM 106.00M FM 106.0M
6 AM 530K AM 522K AM 531K AM530K
7 AM1720K AM1620K AM1602K AM1620K
8 AM 990K AM 990K AM 990K AM 990K
9 AM600K AM 603K AM 603K AM 600K
10 AM 1400K AM 1404K AM 1404K AM 1404K
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

Note:
The unit shown in table is Hz. K is x1000. M is x1,000,000.
The slash indicates that data are not stored in the memory.
FM is stereo mode.

The indication is the same as that of ordinary operation. However,
when the test mode is turned on, the indication shown left lights
for one second.

LCD TEST MODE

When the LCD test mode is turned on, all the segments of LCD light.
Indication

– 8 –

NOTES ON SCHEMATIC DIAGRAM

QT-CD161/141

• Resistor:
To differentiate the units of resistors, the symbol as K and M
are used: the symbol K means 1000 ohm and the symbol M
means 1000 kohm and the resistor without any symbol is an
ohm resistor. The resistor designated "Fusible" is a fuse type
resistor

• Capacitor:
To indicate the unit of capacitor, a symbol P is used: this
symbol P means micro-micro-farad and the unit of the capacitor
without such a symbol is microfarad. As to electrolytic capacitor,
the expression “capacitance/withstand voltage” is used.
(CH), (TH), (RH), (UJ): Temperature compensation
(ML): Mylar type
(P.P.): Polypropylene type

• The indicated voltage in each section is the one measured by
Digital Multimeter between such a section and the chassis
with no signal given.

REF. NO DESCRIPTION POSITION

SW102 RECORD/PLAYBACK PLAYBACK
SW201 FUNCTION/POWER TAPE—TUNER— CD/

OFF—ON
SW202 X-BASS OFF—ON
SW501 TUNER UP OFF—ON
SW502 TUNER DOWN OFF—ON
SW503 BAND OFF—ON

1. Tuner
( ): AM mode
Marking except for ( ): FM mode

2. CD
( ): Play mode
Marking except for ( ): Stop state

3. Deck section
( ): Record mode
Marking except for ( ): Playback mode
Display / Control section:
( ): Active state
Marking except for ( ): CD Function mode at stop state

• Schematic diagram and Wiring Side of P.W.Board for this
model are subject to change for improvement without prior
notice.

• Parts marked with “ ” ( ) are important for

maintaining the safety of the set. Be sure to replace these
parts with specified ones for maintaining the safety and
performance of the set.

REF. NO DESCRIPTION POSITION

SW504 MEMORY OFF—ON
SW505 PRESET DOWN OFF—ON
SW506 PRESET UP OFF—ON
SW507 CD LID OPEN/CLOSE OFF—ON
SW601 TAPE MAIN OFF—ON
SW702 PICKUP IN OFF—ON

FRONT

VIEW

E C B
(S)(G)(D)
(1) (2) (3)

KTA1266 GR
KTA1273 Y
KTC3194 Y
KTC3199 GR
KTC8050 D
KRA102 M
KRA109 M
KRC104 M
KRC107 M

Figure 9 TYPES OF TRANSISTOR

– 9 –

QT-CD161/141

PLAY

20ms

1.00 V
SPO

NORMAL DISC
TN0=01

20ms

2.00 V
CLV+

PLAY

TCD-712 (140mm)
TN0=01

50ms

1.00 V
SPO

50ms

2.00 V
CLV+

WAVEFORMS OF CD CIRCUIT

1

1

2

3

4
5

3

5ms

0.50 V
IC801 20 F.E

5ms

5.0 V
IC801 54 DRF

0.5ms

1.00 V
HF

0.5ms

5.0 V
HFL

0.5ms

5.0 V
TES

0.5ms

1.00 V
H.F

STOP PLAY

FOCUS SERCH

3
1

CUE

1
2

3

REVIEW

6

7

8

9

6

7

8

9

10

11

50ms

10.0 V
JP+

50ms

10.0 V
JP-

50ms

0.50 V
JP

50ms

1.00 V
TE

0.5ms

10.0 V
JP+

0.5ms

10.0 V
JP-

0.5ms

0.50 V
JP

0.5ms

1.00 V
TE

REVIEW

0.5ms

4

5

5.0 V
HFL

0.5ms

5.0 V
TES

1
2

3

10

11

50ms

6

7

8

9

6

7

8

9

10.0 V
JP+

50ms

10.0 V
JP-

50ms

0.50 V
JP

50ms

1.00 V
TE

0.5ms

10.0 V
JP+

0.5ms

10.0 V
JP-

0.5ms

0.50 V
JP

0.5ms

1.00 V
TE

CUE

12

12

5s
100mV
SLD

0.5s
100mV
SLD

PLAY

TCD-712

1

1

– 10 –

TO

MAIN

SECTION

+7.4V

(CD)

QT-CD161/141

+5V

LASER

DRIVER

+5V

Q801

XL801

16.93MHz

23

6

45

62

64

51 37

62

634364

XVDD
VDD

VVDD

LC78622E

SERVO/SIGNAL

FIN1

E

4

CONTROL

EFMO

104412

9

F

XIN

XOUT

LDD
VCC1

FIN2

123

LCHO

IC802

CLV+

CLV–

13

43

44

SLI

14

V/P

15

SLC

EFMIN

IC801

LA9240M

SERVO AMP.

46

HFL

16

CV+

3955385433

TES

TOFF

18 19

17

~

3240

JP–

SL–

31

30

32

11

8
4
2

53

56
57
58

RES. CQCK. COIN

SQOUT. RWC. WRQ

61

1

JP–

JP+

TGL

20

54

DRF

53

CE

52

DAT

51

CL

50

CLK

49

DEF

29

SLD

SLEQ

28
27

SPO

FD

16

TO

SL+

15

CL, DAT, SELIAL CONTROL

CONSTANT

VOLTAGE

Q804

REGULATOR

+5V

+7.4V

30

1

978

IC803

LA6541

FOCUS/TRACKING

3

/SPIN/SLIDE

13
29

28
18

25

DRIVER

20

26

5

21

6

22

24

102511

PICKUP UNIT

FOCUS COIL

TRACKING COIL

Figure 11 BLOCK DIAGRAM (1/3)

– 11 –

TO MAIN

SECTION

M

M701
SPIN

MOTOR

M

M702

SLIDE

MOTOR

TO MAIN

SECTION