Sharp QTCD-250-H, QTCD-250-W Service manual

Illustration: QT-CD250H

QT-CD250H/W

SERVICE MANUAL

No. S3017QTCD250H

QT-CD250H(S) QT-CD250W(S)

• 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.

• Note for users in U.K. Recording and playback of any material may require consent which SHARP is unable to give. Please refer particularly to the provisions of Copyright Act 1956, the Dramatic and Musical Performers Protection Act 1956, the Performers Protection Acts 1963 and 1972 and to any subsequent statutory enactments and orders.

CONTENTS

AC POWER SUPPLY CORD AND AC PLUG ADAPTOR (FOR QT-CD250W) ................................................................ 1

SAFETY PRECAUTION FOR SERVICE MANUAL ........................................................................................................... 2

IMPORTANT SERVICE NOTES (QT-CD250H FOR U.K. ONLY) .................................................................................... 3

VOLTAGE SELECTION (QT-CD250W ONLY).................................................................................................................. 3

SPECIFICATIONS ............................................................................................................................................................. 3

NAMES OF PARTS ........................................................................................................................................................... 4

OPERATION MANUAL ...................................................................................................................................................... 5

DISASSEMBLY.................................................................................................................................................................. 8

REMOVING AND REINSTALLING THE MAIN PARTS..................................................................................................... 8

ADJUSTMENT ................................................................................................................................................................. 10

SCHEMATIC DIAGRAM .................................................................................................................................................. 14

WIRING SIDE OF P.W.BOARD....................................................................................................................................... 16

NOTES ON SCHEMATIC DIAGRAM .............................................................................................................................. 18

TYPES OF TRANSISTOR ............................................................................................................................................... 18

WAVEFORMS OF CD CIRCUIT...................................................................................................................................... 19

TROUBLESHOOTING (CD SECTION) ........................................................................................................................... 20

FUNCTION TABLE OF IC................................................................................................................................................ 24

PARTS GUIDE/EXPLODED VIEW PACKING METHOD (QT-CD250H FOR U.K. ONLY)

AC POWER SUPPLY CORD AND AC PLUG ADAPTOR (FOR QT-CD250W)

QACCA0001SJ00

QPLGA0253AFZZ

Page

QACCB0001SJ00

QACCE0001SJZZ

QPLGA0250AFZZ

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-CD250H/W

SAFETY PRECAUTION FOR SERVICE MANUAL

Precaution to be taken when replacing and servicing the Laser Pickup.

The AEL (Accessible Emission Level) of Laser Power Output for this model is specified to be lower than Class I Requirements. However, the following precautions must be observed during servicing to protect your eyes against exposure to the Laser beam. (1) When the cabinet has been removed, the power is turned on without a compact disc, and the Pickup is on a position outer than

the lead-in position, the Laser will light for several seconds to detect a disc. Do not look into the Pickup Lens. (2) The Laser Power Output of the Pickup inside the unit and replacement service parts have already been adjusted prior to shipping. (3) No adjustment to the Laser Power should be attempted when replacing or servicing the Pickup. (4) Under no circumstances look directly into the Pickup Lens at any time. (5) CAUTION - Use of controls or adjustments, or performance of procedures other than those specified herein may result in

hazardous radiation exposure.

VAROITUS! LAITTEEN KéYTTéMINEN MUULLA KUIN TéSSé KéYTTôOHJEESSA MAINITULLA TAVALLA SAATTAA ALTISTAA KéYTTéJéN TURVALLISUUSLUOKAN 1 YLITTéVéLLE NéKYMéTTôMéLLE LASERSéTEILYLLE.

VARNING - OM APPARATEN ANVéNDS Pè ANNAT SéTT éN I DENNA BRUKSANVISNING SPECIFICERAS. KAN ANVéNDAREN UTSéTTAS FôR OSYNLIG LASERSTRèLNING, SOM ôVERSKRIDER GRéNSEN FôR LASERKLASS 1.

CAUTION-INVISIBLE LASER RADIATION WHEN OPEN. DO NOT STARE INTO BEAM OR VIEW DIRECTLY WITH OPTICAL INSTRUMENTS.

VARNING-OSYNLIG LASERSTRALNING NAR DENNA DEL AR OPPNAD. STIRRA EJ IN I STRALEN OCH BETRAKTA EJ STRALEN MED OPTISKA INSTRUMENT.

ADVERSEL-USYNLIG LASERSTRALING VED ABNING. SE IKKE IND I STRALEN-HELLER IKKE MED OPTISKE INSTRUMENTER.

VARO! AVATTAESSA OLET ALTTIINA NAKYMATON LASERSATEILYLLE. ALA TUIJOTA SATEESEEN ALAKA KATSO SITA OPTISEN LAITTEEN LAPI.

VARNING-OSYNLIG LASERSTRALNING NAR DENNA DEL AR OPPNAD. STIRRA EJ IN I STRALEN OCH BETRAKTA EJ STRALEN GENOM OPTISKT INSTRUMENT.

ADVERSEL-USYNLIG LASERSTRALING NAR DEKSEL APNES. STIRR IKKE INN I STRALEN ELLER SE DIREKTE MED OPTISKE INSTRUMENTER.

QT-CD250H for Europe

QT-CD250H for U.K.

Laser Diode Properties

LASER KLASSE 1 LUOKAN 1 LASERLAITE KLASS 1 LASERAPPARAT

CAUTION

● This Portable CD Stereo System is classified as a CLASS 1 LASER product.

● The CLASS 1 LASER PRODUCT label is located on the rear cover.

● Use of controls, adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.

As the laser beam used in this compact disc player is harmful to the eyes, do not attempt to disassemble the cabinet. Refer servicing to qualified personnel only.

Material: GaAIAs Wavelength: 780 nm Emission Duration: continuous Laser Output: max. 0.6 mW

QT-CD250H for Europe

Laser Diode Properties Material: GaAIAs Wav elength: 780 nm Emission Duration: continuous Laser Output: max. 0.6 mW

CAUTION-INVISIBLE LASER RADIATION WHEN OPEN. DO NOT STARE INTO BEAM OR VIEW DIRECTLY WITH OPTICAL INSTRUMENTS.

VARNING-OSYNLIG LASERSTRALNING NAR DENNA DEL AR OPPNAD. STIRRA EJ IN I STRALEN OCH BETRAKTA EJ STRALEN MED OPTISKA INSTRUMENT.

ADVERSEL-USYNLIG LASERSTRALING VED ABNING. SE IKKE IND I STRALEN-HELLER IKKE MED OPTISKE INSTRUMENTER.

VARO! AVATTAESSA OLET ALTTIINA NAKYMATON LASERSATEILYLLE. ALA TUIJOTA SATEESEEN ALAKA KATSO SITA OPTISEN LAITTEEN LAPI.

VARNING-OSYNLIG LASERSTRALNING NAR DENNA DEL AR OPPNAD. STIRRA EJ IN I STRALEN OCH BETRAKTA EJ STRALEN GENOM OPTISKT INSTRUMENT.

ADVERSEL-USYNLIG LASERSTRALING NAR DEKSEL APNES. STIRR IKKE INN I STRALEN ELLER SE DIREKTE MED OPTISKE INSTRUMENTER.

QT-CD250H for Australia/New Zealand/Philippines/QT-CD250W

– 2 –

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

IMPORTANT SERVICE NOTES (QT-CD250H FOR U.K. ONLY)

Before returning the unit to the customer after completion of a repair or adjustment it is necessary for the following withstand voltage test to be applied to ensure the unit is safe for the customer to use. Setting of Withstanding Voltage Tester and set.

QT-CD250H/W

Set name Withstanding Voltage Tester Test voltage

Set time Set current (Cutoff current) Unit Judgment

Set value

4,240 VPEAK 3,000 VRMS 6 secs 4 mA

WITHSTANDING

VOLTAGE TESTER

OUT

SHORT-CIRCUT AC POWER SUPPLY CORD

PROBE

UNIT

CONNECT THE PROBE TO GND OF CHASSIS SCREW TERMINAL

OK: The “GOOD” lamp lights. NG: The “NG” lamp lights and the buzzor sounds.

VOLTAGE SELECTION (QT-CD250W ONLY)

The voltage selector is located on the AC voltage selector box. If adjustment is necessary, use a screwdriver in order to turn the selector in either direction unitil the correct voltage figure is displayed in the window next the adjustment screw.

SPECIFICATIONS

QT-CD250H/W

● General Power source:

(QT-CD250H for U.K./Europe)

Power source: (QT-CD250H for Australia/ New Zealand/ Philippines)

Power source: (QT-CD250W)

Power consumption: (QT-CD250H)

Power consumption: (QT-CD250W)

AC 230-240 V, 50 Hz DC 9 V ["D" size (UM/SUM-1, R20 or HP-2) battery × 6] DC 4.5 V ["AA" size (UM/SUM-3, R6 or HP-7) battery × 3 for backup memory]

● For customers in Australia and New Zealand; AC 230-240 V, 50 Hz

● For customers in Philippines; AC 220 V, 60 Hz DC 9 V ["D" size (UM/SUM-1, R20 or HP-2) battery × 6] DC 4.5 V ["AA" size (UM/SUM-3, R6 or HP-7) battery × 3 for backup memory]

AC 110-127/220-240 V, 50/60 Hz DC 9 V ["D" size (UM/SUM-1, R20 or HP-2) battery × 6] DC 4.5 V ["AA" size (UM/SUM-3, R6 or HP-7) battery × 3 for backup memory]

8 W

10 W

Output power: (QT-CD250H for Europe)

Output power: (QT-CD250H for U.K./Australia/ New Zealand/ Philippines/ OT-CD250W)

Speakers: 10 cm (4") full-range speaker

Output terminals: Dimensions: Width; 400 mm (15-3/4")

Weight: 2.7 kg (6.0 lbs.)

● Compact disc player

Type: Signal readout: Audio channels: Filter:

D/A converter: Wow and flutter:

RMS; 4.6 W (2.3 W + 2.3 W) (DC operation, DIN 45 324) MPO; 8.4 W (4.2 W + 4.2 W) (AC operation, DIN 45 324)

RMS; 4.6 W (2.3 W + 2.3 W) (DC operation, 10 % T.H.D.) MPO; 8.4 W (4.2 W + 4.2 W) (AC operation, 10 % T.H.D.)

x 2 Headphones; 16-50 ohms (recommended; 32 ohms)

Height; 158 mm (6-1/4") Depth; 212 mm (8-3/8")

without batteries

Compact disc Non-contact, 3-beam semiconductor laser pickup

2 8-times oversampling digital filter

1-bit D/A converter Unmeasurable (less than 0.001% W. peak)

● Radio Frequency

range: (QT-CD250H)

● Radio Frequency

range: (QT-CD250W)

● Tape recorder Frequency

response:

Signal/noise ratio:

Wow and flutter: (QT-CD250H for U.K./Australia/ New Zealand/ Philippines/ QT-CD250W)

Wow and flutter: (QT-CD250H for Europe)

Motor: DC 9 V electric governor Bias system: AC bias Erase system: Magnet erase

FM; 87.5 - 108 MHz AM; 522 - 1,620 kHz

FM; 88 - 108 MHz AM; 531 - 1,602 kHz

50 - 14,000 Hz (Normal tape)

50 dB

0.25 % (WRMS)

0.3 % (DIN 45 511)

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

– 3 –

QT-CD250H/W

NAMES OF PARTS

Illustration: QT-CD250W

2345

10 11

12 13

11.

(TAPE) Record Button

12.

(TAPE) Play Button

13.

(TAPE) Rewind Button

14.

(TAPE) Fast Forward Button

15.

(TAPE) Stop/Eject Button

16.

(TAPE) Pause Button

17.

Cassette Compartment

18.

CD Compartment

19.

CD Eject Button

10.

(CD) Stop Button

(TUNER) Tuning Down Button

11.

(CD) Repeat Button

(TUNER) Band Selector Button

12.

(TUNER) Preset Memory Button

13.

Extra Bass Button

14.

(CD) Play/Pause Button

(TUNER) Tuning Up Button

21 22

14 15

15.

(CD) Track Up/Cue Button

(TUNER) Preset Up Button

16.

(CD) Track Down/Review Button

(TUNER) Preset Down Button

17.

Volume Up/Down Buttons

18.

Stand-by, On/Function Switch

19.

(CD) Play Indicator

20.

(CD) Repeat Indicator

21.

(CD) Pause Indicator

22.

Extra Bass Indicator

23.

(TUNER) Memory Indicator

24.

(TUNER) FM Stereo Mode Indicator

25.

(TUNER) FM Stereo Indicator

26.

Battery Compartment

27.

FM Telescopic Rod Aerial

28.

Headphone Socket

29.

AC Power Input Socket

30.

31.

32.

33.

34.

35.

36.

37.

38.

39.

40.

32 33

VOLTAGE

SELECTOR

AC 220V - 240V

AC 110V - 127V

Backup Memory Battery

Compartment

Voltage Selector (QT-CD250W Only)

(CD) Play/Pause Button

(TUNER) Tuning Up Button (CD) Track Down/Review Button

(TUNER) Preset Down Button (CD) Stop Button

(TUNER) Tuning Down Button (CD) Repeat Button

(TUNER) Band Selector Button (TUNER) Memory Button (TUNER) Clear Button (CD) Track Up/Cue Button

(TUNER) Preset Up Button Extra Bass Button Volume Up/Down Buttons

36 37

39 40

REMOTE CONTROL

Remote sensor

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

Notes:

● 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.

– 4 –

●

6 “D” size batteries (UM/SUM-1, R20, HP-2

or similar)

●

Batteries are not included.

Preparation for use

■

Headphones

■

Volume control

■

Turning the power ON

and to STAND-BY

■

Battery power

TUNER

AC power lead x 1

● QT-CD250H for

customers in

Australia and

New Zealand

● QT-CD250H for

customers in

Philippines

● QT-CD250H for

customers in Europe

● QT-CD250H for

customers in U.K.

● For QT-CD250W

● For QT-CD250W ● For QT-CD250W

To an AC socket

(For Australia/New Zealand)

AC 230 - 240 V, 50 Hz

(For Philippines)

AC 220 V, 60 Hz

(For Europe)

AC 230 - 240 V, 50 Hz

VOLTAGE SELECTOR

110V - 127V

220V - 240V

To AC INPUT

AC 110-127/220-240 V,

50/60 Hz

To an AC socket

■

AC power (For QT-CD250W)

■

AC power (For QT-CD250H)

To AC INPUT

(For U.K.)

AC 230 - 240 V, 50 Hz

To an AC socket

Listening to a tape

To stop playback

Label side up.

Listening to a CD

TUNER

TUNING

PLAY / PAUSE

TUNING

STOP

To stop playback

TUNER

OPERATION MANUAL

QT-CD250H/W

– 5 –

QT-CD250H/W

Recording from CDs

Label side up.

To stop recording

Listening to the radio

TUNING

PLAY / PAUSE

TUNER

■

Aerial adjustment

After use

TUNER

BAND

REPEAT

TUNING

PLAY / PAUSE

STOP

Tune in to the desired station.

Recording from the radio

Do not touch the Laser pickup lens. If fingerprints

or dust accumulate on the pickup, clean it using

commercial cleaning disc (brush type.)

CD pickup cleaning

To stop recording

●

BAND

REPEAT

TUNING

PLAY / PAUSE

STOP

Tune in to the desired station.

TUNER

– 6 –

FM/AM INTERVAL (SPAN) (For QT-CD250W Only)

Before using the unit, be sure to set it for the AM tuning interval (span) used in your area.

To check the tuning span currently selected:

Set the function switch to TUNER.

Press the REPEAT/BAND ( ) button to select the AM band.

● If “AM 531 kHz” is displayed, it means that the radio has been adjusted for a 9 kHz span. If “AM 530 kHz” is displayed, it means that the radio has been adjusted for a 10 kHz span.

T o change from a 9 kHz AM (50 kHz FM) interval to a 10 kHz AM (100 kHz FM) interval:

REPEAT BAND

Set the function switch to TUNER.

Hold down the TUNER MEMORY button and the PRESET button for at least 3 seconds. Release the buttons when “AM SP 9 kHz” and “FM SP 50 kHz” are displayed alternately.

QT-CD250H/W

TUNER MEMORY

[9 kHz ➞ 10 kHz]

[10 kHz ➞ 9 kHz]

The International Telecommunication Union (ITU) has established that member countries should maintain either a 10 kHz or a 9 kHz interval between broadcasting frequencies of any AM station. The illustration shows the 9 kHz interval zones (regions 1 and 3), and the 10 kHz interval zone (region 2). This product is not equipped with a span selector. However, it will be adjusted to 9 kHz AM interval (50 kHz FM interval) when shipped from the factor

ON/STAND-BY

(Function)

kHz

kHz kHz

kHz

kHz kHz

REVIEW PRESET

kHz

Press the REPEAT/BAND ( ) button to select the “AM SP 10 kHz” and “FM SP 100 kHz” are displayed alternately.

Press the TUNER MEMORY button to set it.

● The unit will return back to the normal frequency display .

To return to a 9 kHz AM (50 kHz FM) interval:

Set the function switch to TUNER.

Hold down the TUNER MEMORY button and the PRESET button for at least 3 seconds. Release the buttons when “AM SP 10 kHz” and “FM SP 100 kHz” are displayed alternately.

Press the REPEAT/BAND ( ) button to select the “AM SP 9 kHz” and “FM SP 50 kHz” are displayed alternately.

Press the TUNER MEMORY button to set it.

● The unit will return back to the normal frequency display .

Notes:

● If the backup memory batteries are not inserted and the power is disconnected, it will be automatically returned to a 9 kHz span. If this happens, insert the backup memory batteries first and set the span again.

● When the span is switched, any stations that are memorised will be cancelled.

– 7 –

QT-CD250H/W

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 Top Cabinet/ 1. Screw ................... (A1) x7 8-1

Front Cabinet 2. Socket .................. (A2) x1

2 Power PWB/ 1. Screw ................... (B1) x2 8-2

Terminal PWB 2. Hook..................... (B2) x2

3 Switch PWB 1. Screw ...................(C1) x2 8-2

4 Main PWB/ 1. Socket ..................(D1) x1 8-2

CD Control PWB 2. Screw ................... (D2) x7

(Note) 3. Screw ...................(D3) x1

5 CD Mechanism 1. Screw ................... (E1) x3 8-3

6 Tape Mechanism 1. Screw ................... (F1) x4 8-3

Top Cabinet

3. Screw ................... (A3) x1

3. Socket .................. (B3) x1

4. Hook..................... (B4) x2

2. Socket ..................(C2) x1

3. Hook..................... (C3) x2

4. Screw ...................(C4) x4

4. Solder................... (D4) x3

5. Socket ..................(D5) x3 8-3

6. Screw ...................(D6) x6

7. Hook..................... (D7) x2

SP202

R-CH

SW651 (Voltage Selector) QT-CD250W Only

Terminal PWB

Switch PWB

Power Transformer

(B4)x2

(B2)x2

Power PWB

Power Transformer

(E1)x3 ø2.5x10mm

(C3)x2

(D2)x7 ø3x12mm

Main PWB

Washer

(D5)x1

(C4)x4 ø3x10mm

(C2)x1

(B1)x2 ø3x12mm

Figure 8-2

CD Mechanism

(C1)x2 ø3x12mm

AC Socket

(D5)x2

Tape Mechanism

(D3)x1 ø2.5x8mm

(B3)x1

Top Cabinet

(F1)x4 ø3x10mm

CD Lid Switch

(D1)x1

(D4)x3

(A3)x1 ø3x10mm

Front Cabinet

(A1)x4 ø3x12mm

(A1)x3 ø3x12mm

Main PWB

(A2)x1

REMOVING AND REINSTALLING THE MAIN PARTS

CD MECHANISM SECTION

Perform steps 1 to 5 of the disassembly method to remove the CD mechanism.

How to remove the pickup (See Fig. 8-4.)

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

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

3. Remove the pickup.

Note : (Figure 8-3 and Figure 8-4)

After removing the connector for the optical pickup from the

connector, wrap the conductive aluminium foil around the front end of connector to protect the optical pickup from electrostatic damage.

(D6)x6 ø3x8mm

ø2.6 x6mm

Shaft (A2) x1

(D7)x2

(A1) x2

Pickup

CD Control PWB

Figure 8-3Figure 8-1

Gear (A4) x1

Figure 8-4

Top Cabinet

CD Mechanism

Stop Washer (A3) x1

– 8 –

QT-CD250H/W

TAPE MECHANISM SECTION

Perform steps 1 to 6 of the disassembly method to remove the tape mechanism. (See page 8.)

How to remove the record / playback and erase heads (See Fig. 9-1.)

1. Remove the screws (A1) x 2 pcs., to remove the record/ playback head.

2. Remove the hooks (A2) x 2 pcs., toward the center position

as shown in Fig. 9-1. and then extract the erase head upward.

Note:

After replacing the heads and performing the azimuth adjustment, be sure to apply screwlock.

How to remove the pinch roller (See Fig. 9-2.)

1. Carefully bend the pinch roller pawl in the direction of the

arrow <A>, and remove the pinch roller (B1) upwards.

Hook (A2)x2

Erase Head

Pinch Roller (B1)x1

(A1) x1 ø2x7mm

(A1) x1 ø2x3mm

Record/Playback Head

Figure 9-1

<A>

Pinch Roller Pawl

Figure 9-2

How to remove the belts (See Fig. 9-3.)

1. Remove the main belt (C1) x 1 pc., from the motor pulley.

2. Remove the FF/REW belt (C2) x 1 pc., from the REW/FF

roller.

3. Put on the belts in the reverse order of removal.

Note:

When putting on the belt, ascertain that the belt is not twisted, and clean it.

How to remove the motor (See Figs. 9-4.)

1. Remove the mainbelt.

2. Remove the screw (D1) x 1 pc., to remove the motor mount.

3. Remove the screws (D2) x 2 pcs., to remove the motor.

Note:

When mounting the motor, pay attention to the motor mounting angle.

How to remove the flywheel (See Fig. 9-5.)

1. Remove the belt.

2. Remove the stop washer (E1) x 1 pc., with a small precision

screwdriver to extract the flywheel from the capstan metal.

Note:

When the stop washer is deformed or damaged, replace it with a new one.

Flywheel

FF/REW Belt (C2)x1

Motor

Motor Mount

(E1) x 1 Stop Washer

Main Belt (C1)x1

Washer

Flywheel

Figure 9-3

(D2)x2 Special Screw

(D1)x1 Special Screw

Figure 9-4

Motor

REW/FF Clutch Ass'y

Motor Mount

Motor

How to reinstall the parts

Install each part in the reverse order of the removal with care.

Figure 9-5

– 9 –

QT-CD250H/W

ADJUSTMENT

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

(CNP201 Load resistance: 4 ohms)

• Tape Speed

Test

Tape

Adjusting

Point

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

resistor in Teaminal motor. (M601) (CNP201 Load

Specified

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

Specified Value

- 6 kHz

Specified Value

Value

Instrument

Connection

resistance: 4 ohms)

Instrument

Connection

• AM IF/RF (For QT-CD250H)

Signal generator: 400 Hz, 30%, AM modulated

Test Stage

Frequency Frequency

Display

AM IF 450 kHz 1,620 kHz T3 *1 AM Band — 522 kHz (fL): L4 *3

Coverage 1.0 ±0.05V AM Tracking 600 kHz 603 kHz (fL): L3 *2

1,400 kHz 1,404 kHz (fH): TC1

Setting/

Adjusting

Parts

• AM IF/RF (For QT-CD250W)

Signal generator: 400 Hz, 30%, AM modulated

Test Stage

Frequency

AM IF 450 kHz 1,602 kHz T3 *1

AM Band — 531 kHz (fL): L4 *3 Coverage (9kHz span) 1.0 ±0.05V

AM Band — 530 kHz (fL): L4 *3 Coverage (10kHz span) 1.0 ±0.05V

AM Tracking 603 kHz 603 kHz (fL): L3 *2 (9kHz span) 1,404 kHz 1,404 kHz (fH): TC1

AM Tracking 600 kHz 600 kHz (fL): L3 *2 (10kHz span)

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

Frequency

Display

(9kHz span) 1,620 kHz (10kHz span)

Setting/

Adjusting

Parts

*1. Input: Antenna, Output: Pin 16 of IC1 *2. Input: Antenna, Output: Speaker Terminal

*3. Input: Input is not connected, Output: TP1

CNP101

BIAS OSC.

L301

SW102

Instrument

Connection

Instrument

Connection

• Playback Amplifier Sensitivity Check

Test Tape

Specified Value

MTT-118 1.1 V ± 3 dB Speaker Terminal

Instrument Connection

(Load resistance: 4 ohms)

TUNER SECTION

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

• FM RF

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

Test Stage

Frequency

Display

Serring/

Adjusting

Point

FM Band — 87.5 MHz (fL): L2 *1 Coverage 1.7 V ± 0.05V

FM RF 98.0 MHz 98.0 MHz L1 *2

(10-30 dB)

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

Instrument

Connection

– 10 –

HPJ201 HEADPHONES

MAIN PWB

L3 AM BAR ANTENNA

AM TRACKING fL

IC101

CNP602

3 2 1

AM TRACKING fH

AM IF

FM RF

FM BAND

IC1

COVERAGE fL

TC1

TP1

AM BAND COVERAGE fL

Figure 10 ADJUSTMENT POINTS

CNP201

QT-CD250H/W

A. CD TEST MODE

Set the function switch to "CD" when pressing the "REVIEW(PRESET DOWN )" button together with "STOP(TUNING DOWN)" button.

Step-1. CD Pickup can be move when press the "CUE" button either "REVIEW" button. "CUE" button : CD Pickup move to out side of disc. "REVIEW" button : CD Pickup move to in side of disc. (CD Pickup can't move any more, if reach to most in side.) Note: If the CD Lid open (SW810 open), the unit can be operate Step-1 only and the unit can't operate from Step-2 to Step-5.

Step-2. The LASER light up when press the "PLAY/PAUSE" button.

Step-3. CD disc can be playing mode when press the "PLAY/PAUSE" button during the LASER ON.

The LCD displays indicate the "Track Number" and the "Playing Time".

Step-4. CD disc will be stop and the LASER goes out when pressing the "STOP" button, and return back to Step-1. (CD Pickup position keeps at that point).

Step-5. It can be control to ON/OFF of the Tracking Servo when press the "MEMORY" button during the CD playing mode. (The Servo will be ON when playing mode again, if to make stop mode during the Servo OFF condition.)

The LCD displays indicate the playing time of CD Pickup point. (The LCD displays indicate the playing time at that point when Pickup moving, if press the "CUE" button or press the "REVIEW" button.)

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QT-CD250H/W

B. TUNER TEST MODE

Set the function switch to "TUNER" when pressing the "REVIEW(PRESET DOWN )" button together with "BAND(REPEAT)" button.

The LCD displays indicate the "TunEr" for several seconds. after that, the LCD displays indicate to the normal frequency.

PRESET. NO

P-01 FM 87.50 MHz FM 87.50 MHz FM 87.5 MHz STEREO P-02 FM 108.00 MHz FM 108.00 MHz FM 108.0 MHz STEREO P-03 FM 98.00 Hz FM 98.00 Hz FM 98.0 Hz STEREO P-04 FM 90.00 MHz FM 90.00 MHz FM 90.0 MHz STEREO P-05 FM 106.00 MHz FM 106.00 MHz FM 106.0 MHz STEREO P-06 AM 522 KHz AM 531 KHz AM 530 KHz P-07 AM 1620 KHz AM 1602 KHz AM 1620 KHz P-08 AM 990 KHz AM 990 KHz AM 990 KHz P-09 AM 603 KHz AM 603 KHz AM 600 KHz P-10 AM 1404 KHz AM 1404 KHz AM 1400 KHz P-11 FM 106.00 MHz FM 106.00 MHz FM 106.0 MHz MONO P-12 FM 90.00 MHz FM 90.00 MHz FM 90.0 MHz MONO P-13 FM 98.00 MHz FM 98.00 MHz FM 98.0 MHz MONO P-14 FM 108.00 MHz FM 108.00 MHz FM 108.0 MHz MONO P-15 FM 87.50 MHz FM 87.50 MHz FM 87.5 MHz MONO

QT-CD250H

QT-CD250W (9kHz span)

QT-CD250W

(10kHz span)

FM MODE

Note:

1. The Preset Channel can be change when press the "PRESET UP (CUE) button either "PRESET DOWN (REVIEW)" button. PRESET UP button is pressed : P-01 -> P-02 -> > > > > P-15 -> P-01 PRESET DOWN button is pressed : P-15 -> P-14 -> > > > > P-01 -> P-15

2. The Tuner Mode can be change when press the "BAND (REPEAT)" button. BAND button is pressed : FM stereo -> FM mono -> AM -> FM stereo

C. LCD TEST MODE

Set the function switch to "TUNER (or CD)" when pressing the "REVIEW(PRESET DOWN )" button together with "MEMORY" button.

All of the segments will light up.

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+ 28 hidden pages