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

		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
Illustration: QT-CD250H	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
		Page
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

QACCB0001SJ00

QACCE0001SJZZ					QPLGA0250AFZZ

SHARP CORPORATION	This document has been published to be used
	for after sales service only.
– 1 –	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.

Laser Diode Properties

Material: GaAIAs

Wavelength: 780 nm

Emission Duration: continuous

Laser Output: max. 0.6 mW

LASER KLASSE 1

LUOKAN 1 LASERLAITE

KLASS 1 LASERAPPARAT

QT-CD250H for Europe		QT-CD250H for Europe
CAUTION		Laser Diode Properties
			Material: GaAIAs
			Wavelength: 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
●	This Portable CD Stereo System is classified		STRALEN-HELLER IKKE MED OPTISKE INSTRUMENTER.
			VARO! AVATTAESSA OLET ALTTIINA NAKYMATON LASERSATEILYLLE.
	as a CLASS 1 LASER product.		ALA TUIJOTA SATEESEEN ALAKA KATSO SITA OPTISEN LAITTEEN LAPI.
			VARNING-OSYNLIG LASERSTRALNING NAR DENNA DEL AR OPPNAD.
●	The CLASS 1 LASER PRODUCT label is lo-		STIRRA EJ IN I STRALEN OCH BETRAKTA EJ STRALEN GENOM OPTISKT
			INSTRUMENT.
	cated on the rear cover.		ADVERSEL-USYNLIG LASERSTRALING NAR DEKSEL APNES. STIRR IKKE
			INN I STRALEN ELLER SE DIREKTE MED OPTISKE INSTRUMENTER.

● 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

QT-CD250H for U.K. player is harmful to the eyes, do not attempt to disassemble the cabinet. Refer servicing to

qualified personnel only.

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

– 2 –

QT-CD250H/W

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.

Set name	Set value
Withstanding Voltage Tester
Test voltage	4,240 VPEAK
	3,000 VRMS
Set time	6 secs
Set current (Cutoff current)	4 mA
Unit
Judgment
OK: The “GOOD” lamp lights.

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

WITHSTANDING

VOLTAGE TESTER

PROBE

AC

OUT

UNIT

SHORT-CIRCUT	CONNECT THE PROBE
AC POWER	TO GND OF CHASSIS
SUPPLY CORD	SCREW TERMINAL

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:

Output terminals: Dimensions:

Weight:

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.)

10 cm (4") full-range speaker x 2

Headphones; 16-50 ohms (recommended; 32 ohms) Width; 400 mm (15-3/4")

Height; 158 mm (6-1/4") Depth; 212 mm (8-3/8") 2.7 kg (6.0 lbs.)

without batteries

● Compact disc player

Type:	Compact disc
Signal	Non-contact, 3-beam semi-
readout:	conductor laser pickup
Audio
channels:	2
Filter:	8-times oversampling
	digital filter
D/A converter:	1-bit D/A converter
Wow and	Unmeasurable
flutter:	(less than 0.001% W. peak)

● Radio
Frequency	FM; 87.5 - 108 MHz
range:	AM; 522 - 1,620 kHz
(QT-CD250H)
● Radio
Frequency	FM; 88 - 108 MHz
range:	AM; 531 - 1,602 kHz
(QT-CD250W)
● Tape recorder
Frequency
response:	50 - 14,000 Hz
	(Normal tape)
Signal/noise
ratio:	50 dB
Wow and
flutter:	0.25 % (WRMS)
(QT-CD250H for
U.K./Australia/
New Zealand/
Philippines/
QT-CD250W)
Wow and
flutter:	0.3 % (DIN 45 511)
(QT-CD250H for
Europe)
Motor:	DC 9 V electric governor
Bias system:	AC bias
Erase
system:	Magnet erase

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

– 3 –

QT-CD250H/W

NAMES OF PARTS

Illustration: QT-CD250W

1	2	3	4	5	6	7	8	9
10
11								14
								15

12					16
13
					17
18
19	20 21	22	23	24	25

26 27

28 29

	VOLTAGE
30	SELECTOR
	AC
	220V - 240V
	31
	AC
	110V - 127V

	32	36
		37
	33	38
	34	39
	35	40

1.	(TAPE) Record Button	15.	(CD) Track Up/Cue Button	30. Backup Memory Battery
2.	(TAPE) Play Button	16.	(TUNER) Preset Up Button		Compartment
3.	(TAPE) Rewind Button		(CD) Track Down/Review Button	31. Voltage Selector (QT-CD250W Only)
4.	(TAPE) Fast Forward Button	17.	(TUNER) Preset Down Button	32.	(CD) Play/Pause Button
5.	(TAPE) Stop/Eject Button		Volume Up/Down Buttons		(TUNER) Tuning Up Button
6.	(TAPE) Pause Button	18.	Stand-by, On/Function Switch	33.	(CD) Track Down/Review Button
7.	Cassette Compartment	19.	(CD) Play Indicator		(TUNER) Preset Down Button
8.	CD Compartment	20.	(CD) Repeat Indicator	34.	(CD) Stop Button
9.	CD Eject Button	21.	(CD) Pause Indicator	35.	(TUNER) Tuning Down Button
10.	(CD) Stop Button	22.	Extra Bass Indicator		(CD) Repeat Button
11.	(TUNER) Tuning Down Button	23.	(TUNER) Memory Indicator	36.	(TUNER) Band Selector Button
	(CD) Repeat Button	24.	(TUNER) FM Stereo Mode Indicator		(TUNER) Memory Button
	(TUNER) Band Selector Button	25.	(TUNER) FM Stereo Indicator	37.	(TUNER) Clear Button
12.	(TUNER) Preset Memory Button	26. Battery Compartment		38.	(CD) Track Up/Cue Button
13.	Extra Bass Button	27. FM Telescopic Rod Aerial		39.	(TUNER) Preset Up Button
14.	(CD) Play/Pause Button	28. Headphone Socket			Extra Bass Button
	(TUNER) Tuning Up Button	29. AC Power Input Socket		40.	Volume Up/Down Buttons

REMOTE CONTROL

	Remote sensor
	15	0.2 m - 6 m
	15
		(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 –

– 5 –

1 Preparation for use

AC power lead x 1	● QT-CD250H for	● QT-CD250H for	● QT-CD250H for
● QT-CD250H for	customers in	customers in	customers in Europe
customers in U.K.	Australia and	Philippines
	New Zealand

● For QT-CD250W

● For QT-CD250W ● For QT-CD250W

■ AC power (For QT-CD250H)

(For U.K.)

AC 230 - 240 V, 50 Hz

To AC INPUT

To an AC socket (For Australia/New Zealand)

AC 230 - 240 V, 50 Hz

(For Philippines)	(For Europe)
AC 220 V, 60 Hz	AC 230 - 240 V, 50 Hz

■ AC power (For QT-CD250W)

AC 110-127/220-240 V,

50/60 Hz

1

To AC INPUT

2

VOLTAGE SELECTOR

AC

220V - 240V

AC	To an AC socket
110V - 127V

To an AC socket

■ Battery power

2

3

1

5 6

4

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

●Batteries are not included.

■ Headphones	■ Turning the power ON	■ Volume control
	and to STAND-BY
	TUNER
	1

2 Listening to a CD
1	2	3	4
	TUNER

Label side up.

To stop playback		5	OPERATION
STOP		PLAY / PAUSE
TUNING		TUNING
3 Listening to a tape			MANUAL
1	2	To stop playback

TUNER

4		3
	2	CD250H/WQT-

– 6 –

4 Listening to the radio

1

TUNER

2 BAND	3	STOP	PLAY / PAUSE	After use
REPEAT		TUNING	TUNING
				TUNER
		Tune in to the desired station.
■ Aerial adjustment		FM		AM
5 Recording from CDs
3	To stop recording		1	2
				TUNER

Label side up.

4

5	6	PLAY / PAUSE
		TUNING

6 Recording from the radio
1	4	To stop recording	5

TUNER

7

6

8

2	BAND	3	STOP	PLAY / PAUSE
	REPEAT		TUNING	TUNING

Tune in to the desired station.

CD pickup cleaning

● Do not touch the Laser pickup lens. If fingerprints or dust accumulate on the pickup, clean it using commercial cleaning disc (brush type.)

CD250H/W-QT

3	4

QT-CD250H/W

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

REPEAT
BAND
TUNER	ON/STAND-BY	REVIEW
MEMORY	(Function)	PRESET
[9 kHz 10 kHz]
	kHz	kHz
	kHz	kHz
[10 kHz 9 kHz]
	kHz	kHz
	kHz	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 factory.

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:

1 Set the function switch to TUNER.

2 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.

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

1 Set the function switch to TUNER.

2 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.

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

4 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:

1 Set the function switch to TUNER.

2 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.

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

4 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		(C3)x2
	Caution on Disassembly
	Follow the below-mentioned notes when disassembling the						Switch PWB
	unit and reassembling it, to keep it safe and ensure excellent						SW651
							(Voltage Selector)
	performance:
							QT-CD250W Only
	1. Take cassette tape and compact disc out of the unit.						Power Transformer
	2. Be sure to remove the power supply plug from the wall
	outlet before starting to disassemble the unit.							(D2)x7
	3. Take off nylon bands or wire holders where they need to							ø3x12mm
	be removed when disassembling the unit. After servicing							Main PWB
	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		(B4)x2
							Terminal
	1	Top Cabinet/	1. Screw		(A1) x7	8-1	PWB
		Front Cabinet	2. Socket ..................		(A2) x1
			3.	Screw ...................	(A3) x1
	2	Power PWB/	1.	Screw ...................	(B1) x2	8-2	(B2)x2
		Terminal PWB	2. Hook .....................		(B2) x2		Power PWB
			3.	Socket	(B3) x1
							Power Transformer
			4.	Hook .....................	(B4) x2
	3	Switch PWB	1. Screw ...................		(C1) x2	8-2
			2.	Socket ..................	(C2) x1		(E1)x3
			3.	Hook .....................	(C3) x2		ø2.5x10mm
			4.	Screw ...................	(C4) x4			Washer
	4	Main PWB/	1.	Socket	(D1) x1	8-2
		CD Control PWB	2. Screw ...................		(D2) x7			(D5)x1
		(Note)	3. Screw ...................		(D3) x1
			4.	Solder ...................	(D4) x3
			5.	Socket ..................	(D5) x3	8-3
			6.	Screw ...................	(D6) x6
			7.	Hook .....................	(D7) x2
	5	CD Mechanism	1. Screw ...................		(E1) x3	8-3
	6	Tape Mechanism	1. Screw ...................		(F1) x4	8-3
		Top Cabinet

SP202

R-CH

(C4)x4

ø3x10mm (C1)x2

ø3x12mm

(D3)x1

ø2.5x8mm

CD Lid Switch

(C2)x1

(B3)x1

(D1)x1

(D4)x3

Top Cabinet

AC Socket

(B1)x2

ø3x12mm

Figure 8-2

	CD Mechanism	(F1)x4
		ø3x10mm
	(D5)x2

Tape

Mechanism

	(D6)x6
(A3)x1	ø3x8mm
	(D7)x2
ø3x10mm
Front Cabinet	Top Cabinet

	(A1)x4	Main
		PWB
	ø3x12mm
		(A2)x1

(A1)x3

ø3x12mm

Figure 8-1

CD Control

PWB

Figure 8-3

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.

– 8 –

(A1) x2 ø2.6 x6mm

Pickup	CD
	Mechanism

	Stop
	Washer
	Gear (A3) x1
Shaft	(A4) x1
(A2) x1
	Figure 8-4

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.

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.

QT-CD250H/W

Hook	(A1) x1
(A2)x2	ø2x7mm

(A1) x1 ø2x3mm

Record/Playback

Head

Figure 9-1

	<A>
Pinch Roller	Pinch Roller
(B1)x1	Pawl

Figure 9-2

Main Belt (C1)x1

Motor

Flywheel

FF/REW Belt	REW/FF
(C2)x1	Clutch Ass'y

Motor

Motor Mount

Figure 9-3

	(D2)x2
	Special	Motor
	Screw
		Mount
	(D1)x1
	Special
	Screw
		Motor

Figure 9-4

(E1) x 1 Stop Washer

Washer

Flywheel

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	Specified Value
PLAY: TW-2412	Over 120 g

• Torque Check

Torque Meter	Specified Value
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	Specified Value
MTT-114	Output: Speaker Terminal
	(CNP201 Load resistance: 4 ohms)

• Tape Speed

Test	Adjusting	Specified	Instrument
Tape	Point	Value	Connection
MTT-111	Variable	3,000 ± 90 Hz	Output: Speaker
	resistor in		Teaminal
	motor. (M601)		(CNP201 Load
			resistance: 4 ohms)

TAPE SECTION

Position of each switch or control

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

• Bias Oscillation

Adjustment Point	Specified Value	Instrument
		Connection
L301	82 kHz ± 6 kHz	Pin 2 of CNP201
	- 6 kHz

∙ AM IF/RF (For QT-CD250H)

Signal generator: 400 Hz, 30%, AM modulated

Test Stage	Frequency	Frequency	Setting/	Instrument
		Display	Adjusting	Connection
			Parts
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

∙ AM IF/RF (For QT-CD250W)

Signal generator: 400 Hz, 30%, AM modulated

Test Stage	Frequency	Frequency	Setting/	Instrument
		Display	Adjusting	Connection
			Parts
AM IF	450 kHz	1,602 kHz	T3	*1
		(9kHz span)
		1,620 kHz
		(10kHz span)
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

*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.	4 3 2 1
		L301	SW102

• Playback Amplifier Sensitivity Check

11 1

IC101

12 2

Test Tape	Specified Value	Instrument Connection
MTT-118	1.1 V ± 3 dB	Speaker Terminal	HPJ201	CNP602	CNP201
		(Load resistance: 4 ohms)	HEADPHONES	3	3 2 1
				2
				1

	TUNER SECTION						MAIN PWB
	fL: Low-range frequency
	fH: High-range frequency
	∙ FM RF							AM
	Signal generator: 1 kHz, 75 kHz dev., FM modulated						L3
								TRACKING fH
							AM BAR
	Test Stage Frequency			Frequency	Serring/	Instrument	ANTENNA		TC1	R7
							FM RF
				Display	Adjusting	Connection
								L1		L4
					Point
							AM IF			TP1
	FM Band	—		87.5 MHz	(fL): L2	*1			L2
							T3			AM BAND
	Coverage				1.7 V ± 0.05V		1	24
										COVERAGE fL
	FM RF	98.0 MHz		98.0 MHz	L1	*2	IC1	16	FM BAND
		(10-30 dB)							COVERAGE fL
							12	13
	*1. Input: Antenna,		Output: TP1				AM
	*2. Input: Antenna,		Output: Speaker terminal
							TRACKING fL

Figure 10 ADJUSTMENT POINTS

– 10 –

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.)

– 11 –

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	QT-CD250H	QT-CD250W	QT-CD250W	FM MODE
			(9kHz span)	(10kHz span)
	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

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.

– 12 –