JVC UXG-1 Service manual

SERVICE MANUAL

MICRO COMPONENT SYSTEM

MB41220056

UX-G1

Area suffix

US ------------------------ Singapore UB ---------------------- Hong Kong UT ---------------------------- Taiwan UW ----------- Brazil,Mexico,Peru UY ------------------------ Argentina

TIMER

TIMER SET

STANDBY/ON

ON/OFF

REPEAT

RANDOM SLEEP

REMAIN

TUNER/

TAPE CD

BAND

BEAT CUT

DISPLAY/ CLOCK SET

SOUND/

MUTING

BASS

FM MODEPROGRAM

VOLUME

STANDBY/ON

VOLUME

MICRO COMPONENT SYSTEM

REMOTE CONTROL

CD SYNCHRO RECORDING

OPEN

CA-UXG1 SP-UXG1 SP-UXG1

Lead free solder used in the board (material : Sn-Ag-Cu, melting point : 219 Centigrade)

TABLE OF CONTENTS

1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17

No.MB412

2005/6

SPECIFICATION

Amplifier Section-CA-UXG1

Output Power (IEC 268-3) 10 W (5 W + 5 W) at 4 Ω (10% THD) Speakers/Impedance 4 Ω - 16 Ω

Tuner FM tuning range 87.50 MHz-108.00 MHz

AM tuning range AM 9 kHz intervals: 531 kHz-1 710 kHz

AM 10 kHz intervals: 530 kHz-1 710 kHz

CD player Dynamic range 85 dB

Signal-to-noise ratio 85 dB

Wow and flutter Immeasurable

Cassette deck Frequency response Normal (type I) 100 Hz-10 000 Hz

Wow and flutter 0.35 % (WRMS)

General Power requirement AC 110 V-127 V/220 V-240 V adjustable with the voltage selector 50 Hz/60 Hz

Power consumption 22 W (at operation)

4.5 W (on standby)

Dimensions (W/H/D) (approx.) 145 mm × 209 mm × 226 mm

Mass (approx.) 3.0 kg

Speaker Section-SP-UXG1

Type Full range Bass-reflex type

Speakers 10 cm cone × 1

Power handling capacity 5 W

Impedance 4 Ω

Frequency range 100 Hz to 15 kHz

Dimensions (W/H/D) (approx.) 135 mm × 209 mm × 152 mm

Mass (approx.) 1.3 kg each

Design and specifications are subject to change without notice.

1-2 (No.MB412)

SECTION 1

PRECAUTION

1.1 Safety Precautions

(1) This design of this product contains special hardware and

many circuits and components specially for safety purposes. For continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Services should be performed by qualified personnel only.

(2) Alterations of the design or circuitry of the product should

not be made. Any design alterations of the product should not be made. Any design alterations or additions will void the manufacturers warranty and will further relieve the manufacture of responsibility for personal injury or property damage resulting therefrom.

(3) Many electrical and mechanical parts in the products have

special safety-related characteristics. These characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in the Parts List of Service Manual. Electrical components having such features are identified by shading on the schematics and by ( ) on the Parts List in the Service Manual. The use of a substitute replacement which does not have the same safety characteristics as the recommended replacement parts shown in the Parts List of Service Manual may create shock, fire, or other hazards.

(4) The leads in the products are routed and dressed with ties,

clamps, tubings, barriers and the like to be separated from live parts, high temperature parts, moving parts and/or sharp edges for the prevention of electric shock and fire hazard. When service is required, the original lead routing and dress should be observed, and it should be confirmed that they have been returned to normal, after reassembling.

(5) Leakage shock hazard testing

After reassembling the product, always perform an isolation check on the exposed metal parts of the product (antenna terminals, knobs, metal cabinet, screw heads, headphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.Do not use a line isolation transformer during this check.

• Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester", measure the leakage current from each exposed metal parts of the cabinet, particularly any exposed metal part having a return path to the chassis, to a known good earth ground. Any leakage current must not exceed 0.5mA AC (r.m.s.).

• Alternate check method Plug the AC line cord directly into the AC outlet. Use an

AC voltmeter having, 1,000Ω per volt or more sensitivity in the following manner. Connect a 1,500Ω 10W resistor paralleled by a 0.15µF AC-type capacitor between an ex-

posed metal part and a known good earth ground. Measure the AC voltage across the resistor with the AC

voltmeter. Move the resistor connection to each exposed metal part, particularly any exposed metal part having a return path to the chassis, and measure the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each measurement. Voltage measured any must not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.).

AC VOLTMETER (Having 1000 ohms/volts, or more sensitivity)

0.15 F AC TYPE

Place this probe on

1500 10W

Good earth ground

1.2 Warning

(1) This equipment has been designed and manufactured to

meet international safety standards.

(2) It is the legal responsibility of the repairer to ensure that

these safety standards are maintained.

(3) Repairs must be made in accordance with the relevant

safety standards.

(4) It is essential that safety critical components are replaced

by approved parts.

(5) If mains voltage selector is provided, check setting for local

voltage.

1.3 Caution

Burrs formed during molding may be left over on some parts of the chassis. Therefore, pay attention to such burrs in the case of preforming repair of this system.

1.4 Critical parts for safety

In regard with component parts appearing on the silk-screen printed side (parts side) of the PWB diagrams, the parts that are printed over with black such as the resistor ( ), diode ( ) and ICP ( ) or identified by the " " mark nearby are critical for safety. When replacing them, be sure to use the parts of the same type and rating as specified by the manufacturer. (This regulation dose not Except the J and C version)

each exposed metal part.

(No.MB412)1-3

1.5 Preventing static electricity

Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged, can destroy the laser diode in the traverse unit (optical pickup). Take care to prevent this when performing repairs.

1.5.1 Grounding to prevent damage by static electricity

Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as laser products. Be careful to use proper grounding in the area where repairs are being performed.

(1) Ground the workbench

Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate over it before placing the traverse unit (optical pickup) on it.

(2) Ground yourself

Use an anti-static wrist strap to release any static electricity built up in your body.

(caption) Anti-static wrist strap

Conductive material (conductive sheet) or iron palate

(3) Handling the optical pickup

• In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optical pickup are shorted. After replacement, return the shorted parts to their original condition. (Refer to the text.)

• Do not use a tester to check the condition of the laser diode in the optical pickup. The tester's internal power source can easily destroy the laser diode.

1.6 Handling the traverse unit (optical pickup)

(1) Do not subject the traverse unit (optical pickup) to strong shocks, as it is a sensitive, complex unit. (2) Cut off the shorted part of the flexible cable using nippers, etc. after replacing the optical pickup. For specific details, refer to the

replacement procedure in the text. Remove the anti-static pin when replacing the traverse unit. Be careful not to take too long a

time when attaching it to the connector. (3) Handle the flexible cable carefully as it may break when subjected to strong force. (4) I t is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.

1.7 Attention when traverse unit is decomposed

*Please refer to "Disassembly method" in the text for the pickup unit.

• Apply solder to the short land sections before the flexible wire is disconnected from the connecto on the servo board. (If the flexible wire is disconnected without applying solder, the pickup may be destroyed by static electricity.)

• In the assembly, be sure to remove solder from the short land sections after connecting the flexible wire.

CD pickup board

1-4 (No.MB412)

Short-circuit point

Card wire

CD mechanism board

CN601

1.8 Important for laser products

1.CLASS 1 LASER PRODUCT

2.DANGER : Invisible laser radiation when open and inter

lock failed or defeated. Avoid direct exposure to beam.

3.CAUTION : There are no serviceable parts inside the

Laser Unit. Do not disassemble the Laser Unit. Replace

the complete Laser Unit if it malfunctions.

4.CAUTION : The CD,MD and DVD player uses invisible

laser radiation and is equipped with safety switches which

prevent emission of radiation when the drawer is open and

the safety interlocks have failed or are defeated. It is

dangerous to defeat the safety switches.

5.CAUTION : If safety switches malfunction, the laser is able

to function.

6.CAUTION : Use of controls, adjustments or performance of

procedures other than those specified here in may result in

hazardous radiation exposure.

Please use enough caution not to see the beam directly or touch it in case of an adjustment or operation check.

REPRODUCTION AND POSITION OF LABELS

WARNING LABEL

CAUTION : Visible and Invisible

laser radiation when open and interlock failed or defeated. AVOID DIRECT EXPOSURE TO BEAM. (e)

CLASS 1 LASER PRODUCT

ADVARSEL : Synlig og usynlig laserstråling når maskinen er åben eller interlocken fejeler. Undgå direkte eksponering til stråling. (d)

CAUTION : Visible and Invisible laser radiation when open and interlock failed or defeated. AVOID DIRECT EXPOSURE TO BEAM. (e)

VARNING : Synlig och osynling laserstrålning när den öppnas och spärren är urkopplad. Betrakta ej strålen. (s)

VARO : Avattaessa ja suojalukitus ohitettuna tai viallisena olet alttiina näkyvälle ja näkymättömälle lasersäteilylle. Vältä säteen kohdistumista suoraan itseesi. (f)

ADVARSEL : Synlig og usynlig laserstråling når maskinen er åben eller interlocken fejeler. Undgå direkte eksponering til stråling. (d)

VARO : Avattaessa ja suojalukitus ohitettuna tai viallisena olet alttiina näkyvälle ja näkymättömälle lasersäteilylle. Vältä säteen kohdistumista suoraan itseesi. (f)

(No.MB412)1-5

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

1-6 (No.MB412)

SECTION 3

DISASSEMBLY

3.1 Main body

3.1.1 Removing the Rear cover assembly (See Fig.1 to 5)

(1) Remove the two screws A, the two screws B on the back

of the body. (2) Remove the four screws D on each side of the body. (3) Remove the two screws E on the bottom of the body. (4) Move the front panel assembly in the direction of the arrow

and remove. Disconnect the wire from connector CN901

on the transformer board and FM-ANT connector CN203

on the main board.

Caution:

When reassembling, set the joint a on the right and left side to the groove, and move.

CD mechanism assembl

Rear cover assembly

Front panel assembly

Fig.3

CD mechanism assembly

Joint a

Fig.1

Front panel assembly

Rear cover assembly

FM-ANT

Joint a

Fig.4

Transformer board

Rear cover assembly

CN901

Front panel assembly

Fig.2

Main board

CN203

Fig.5

(No.MB412)1-7

3.1.2 Removing the Main board (See Fig.6, 7)

• Prior to performing the following procedure, remove the rear

cover assembly. (1) Disconnect the wire from all connectors on the main board. (2) Cut off the band setting the wire. (3) Remove the two screws F and release the joint b.

Front panel

assembly

CN301

CN370

CN401

CN402

CN260

CD mechanism

assembly

CN850

CN851

Joint b

CD mechanism

assembly

CN801

Main board

Fig.6

Front panel assembly

Main board

Fig.7

1-8 (No.MB412)

3.1.3 Removing the CD mechanism assembly and the Switch board

(See Fig.8 to 10)

• Prior to performing the following procedure, remove the rear

cover assembly and the main board. (1) Cut off the four bands setting the wires. (2) Disconnect the wire from connector on the CD open switch

and CN603 (3) Remove the two screws G on the front panel assembly. (4) Release the joint d of the CD mechanism assembly. (5) Remove the five screws H attaching the switch board to the

CD mechanism assembly. (6) Unsolder the switch board, if necessary.

, CN606 on the CD mechanism board.

Front panel

assembly

Band

Open switch connecter

Band

Fig.8

CD mechanism

assembly

Joint d

CD mechanism

assembly

CN603

CD mechanism board

CN606

Front panel assembly

Fig.9

CN606

CN603

Open switch connecter

Front panel

assembly

Solder point

Switch board

Fig.10

CD mechanism

assembly

(No.MB412)1-9

3.1.4 Removing the CD mechanism board, CD mechanism (See Fig.11 to 14)

• Prior to performing the following procedure, remove the rear

cover assembly, the main board and the CD mechanism assembly.

Caution:

Make sure to solder the short-circuit point on the CD pickup board before disconnecting the card wire from connector

on the CD mechanism board and from the CD pickup

CN601

board. If you do not follow this instruction, the pickup may be damaged. (1) Remove the four screws J on the CD mechanism assem-

bly. (2) Disconnect the wire from connector of the CD motor board. (3) Solder the short-circuit point on the CD pickup board, and

disconnect the wire from the CD pickup board.

Caution:

To reattach the CD mechanism board, connect the card wire to connector CN601 and to the CD pickup board, then unsolder the short-circuit point.

(4) Remove the screw K attaching the wire on the CD mecha-

nism board.

Caution:

The metal washer and nut come off.

(5) Remove the four screws L attaching the CD mechanism.

on the CD mechanism board

Short-circuit point

CD pickup board

CD mechanism board

CN601

Card wire

Fig.12

CD motor board

connecter

Front panel

CD mechanism

board

Switch board

CD mechanism

assembly

CD mechanism

assembly

CD mechanism

assembly

CN601

Fig.11

Connecter

CD motor board

CD mechanism board

Nut

Connecter

Fig.13

CD mechanism

1-10 (No.MB412)

Fig.14

3.1.5 Removing the Headphone board (See Fig.15)

• Prior to performing the following procedure, remove the rear

cover assembly, the main board and the CD mechanism assembly. (1) Remove the screw M on the bracket and pull out the head-

phone board.

3.1.6 Removing the LCD board (See Fig.16)

• Prior to performing the following procedure, remove the rear

cover assembly, the main board and the CD mechanism assembly. (1) Remove the ten screws N and the two screws P on the

Front panel assembly.

CD mechanism

assembly

Switch board

Fig.15

Head phones

bracket

Head phones

board

3.1.7 Removing the Cassette mechanism (See Fig.17)

• Prior to performing the following procedure, remove the rear

cover assembly and the main board. (1) Remove the four screws Q on the front panel assembly and

press the eject button on the front side to remove the cassette mechanism assembly.

Front panel

assembly

LCD board

Fig.16

Cassette mechanism

assembly

Front panel

assembly

Fig.17

(No.MB412)1-11

3.1.8 Removing the transformer board (See Fig.18 to 20)

• Prior to performing the following procedure, remove the rear

cover assembly. (1) From the rear cover assembly, remove the screw R attach-

ing the transformer board support.

(2) Remove the transformer board from the rear panel assem-

bly in the direction of the arrow.

(3) From the transformer board, remove the screw T attaching

the transformer board support. (4) Remove the tap attaching the transformer board cover. (5) Unsolder the eight points on the wire on the transformer as-

sembly.

3.1.9 Removing the transformer (See Fig. 18,21)

• Prior to performing the following procedure, remove the rear

cover assembly and the transformer board. (1) From the rear cover assembly, remove the four screws U

attaching the transformer. (2) Remove the two screws Y setting the power cord. (3) Remove the two screws A' attaching the voltage selector

on the bottom of the body. (4) Remove the transformer from the rear panel assembly in

the direction of the arrow.

Rear cover assembly

Transformer board

Transformer board support

Rear cover assembly

Transformer board cover

Solder point

Transformer board

Voltage selector

Fig.19

Transformer

Fig.18

Solder point

Rear cover assembly

Solder point

Ta p

Transformer board

Solder point

Fig.20

1-12 (No.MB412)

Voltage selector

Fig.21

3.1.10 Removing the FM-ANT board (See Fig.22)

• Prior to performing the following procedure, remove the rear

cover assembly. (1) Remove the screw B' on the rear cover assembly. (2) Unsolder the FM-ANT wire on the FM-ANT board.

FM-ANT board

Rear cover assembly

Fig.22

(No.MB412)1-13

SECTION 4

ADJUSTMENT

4.1 Measuring instructions required for adjustment

• AM signal generator

• FM signal generator

• Inter medicate frequency sweep generator

• FM stereo signal generator

• Low-frequensy oscillator (osillation frequency 50 Hz - 20 kHz, 0 dB output with 600 Ω impedance)

• Attenuator (600 Ω impedance)

• Electoronic voltmeter

• Distortion meter

• Torque gauge (cassette for CTG-N)

• Wow & flutter meter

• Frequency counter meter

4.2 Test tape

• Playback tape VT712 (tape speed, wow flutter) VT724 (reference level) VT703L (head azimuth) VT738 (frequency responce)

• Recording tape AC225 (type l)

• Power supply voltage AC220V - 240V 50Hz

4.3 Measuring instruments

• Radio section FM : 1 kHz, 22.5kHz deviation

FM stereo : 1 kHz, 67.5 kHz deviation, pilot signal 7.5 kHz AM : 1 kHz, 30% modulation

Reference output : 0 dB (1 V) 4 Ω Headphone output : -10 dB (0.1V) 32 Ω

4.4 Amplifier section

• Reference output :

Speaker output 0 dB (1 V) / 4 Ω Headphone output -10 dB (0.1 V) / 32 Ω

4.5 CD section

• Test disc : CTS-1000 (JVC) TCD-731R (A-BEX) TCD-712R (A-BEX) TCD-785 (A-BEX)

1-14 (No.MB412)

4.6 Cassette amplifier section

Item Measuring condition Check and adjustment procedure Standard value Adjusting part

Head azimuth adjustment

Tape speed and wow/flutter check and adjustment

PB frequency responce check

Bias frequency check

REC and PB frequency responce adjustment

Test tape : VT703 Signal output terminal : PHONES (with 32 ohm load)

Test tape : VT712 Signal output terminal : PHONES (with 32 ohm load)

Test tape : VT738 Signal output terminal : PHONES (with 32 ohm load)

Test tape : normal Signal output terminal : Casssette R/P head

Test tape : AC225 Signal input : FM 22.5 dev, 60dBu with emphasis Signal output terminal : PHONES (with 32 ohm load)

4.7 Tuner section

1.Plyback the test tape VT703.

2.Adjust the head azimuth adjusting screw so that the phase difference between the R and L channels is minimized at an output level that is within +/- 2dB of the maximum output level. After this adjustment, lock the head azimuth adjusting screw with screw sealant to cover more than a half of the screw head.

3.When the head azimuth is maladjusted, correct it with the head azimuth adjusting screw.

1.Plyback the test tape VT712 by the end of position.

2.Connect a frequency counter and check that it reads between 2940 and 3090 Hz. If not, adjust the frequenct with the motor semifixed resistor.

3.Check that the wow / flutter is 0.38% (unweighted).

Playback the test tape VT738 while confirming that deviation between the 1 kHz signal and 8 kHz signal should be 0 (+3 to -6) dB.

Set the TUNER or CD function and with TAPE to record. Check to see if the frequency at the measuring point (R335 or R336) is 60 kHz +/-1 kHz if not adjust T360 until the frequency counter indicates 60 kHz +/- 1 kHz.

At TUNER, set the BAND to the FM position, and record the reference 1 kHz signal and 8 kHz signal altemately repeatedly. While playing back the recorded signal differ from that of the 1 kHz signal by within 0 (+3 to 6) dB.

Output level : within +/-2dB of maximum output level

Phase defference L and R channels: minimum

2940 to 3090 Hz

within 0.38% (unweighted)

deviation between 1 kHz and 8 kHz : 0 (+3 to -6) dB.

Level difference between REC and PB : within 0 (+3 to 6) dB

Head azimuth adjusting screw (to be used only after head replacement)

Tape speed : motor semifixed resistor

check only

L203

Item Measuring condition Check and adjustment procedure Standard value Adjusting part

AM IF adjustment

AM tracking adjustment

Tuner 114 kHz filter the waves adjustment

Signal input : Loop antenna Signal output : IC201 pin 18

Signal input : Loop antenna Signal output : PHONES (with 32 ohm load)

Signal input : IC101 pin 19 Signal output : IC101 pin 18

1.Set the intermediate frequency sweep generator to AM 450 kHz.

2.Adjust the T203 from maximum and center output.

1.Set the TUNER at 522 kHz adjust T201 until the test pin of R245 voltage at

1.55 V +/- 0.1 V.

2.Set the TUNER at 1629 kHz, check the pin of R245 voltage at 8.4 V +/- 6V.

3.Set the TUNER ang S/G at 612 kHz, adjust T202 for maximum output.

4.Set the TUNER and S/G at 1404 kHz, adjust T201 for maximum output.

5.Repwat the above step 3 and 4.

1.Set the unit in standby mode. Input 114 kHz signal to IC101 pin 19.

2.Adjust the T204 for output voltage minimum.

T203

T201

R245

TC201

T204

(No.MB412)1-15

4.8 Location of adjusting parts

Cassette mechanism section

Main board assembly

(AM RF)

T202

Tape speed adj.

(AM IF)

T203

CASSETTE

MOTOR

TC201

R245

(AM VT)

(AM RF)

T201

(AM OSC)

T204

(114 kHz)

1-16 (No.MB412)

T360

(BIAS FREQUENCY)

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