Jvc RC-BX33-SL Service Manual

RC-BX33SL

SERVICE MANUAL

PORTABLE CD SYSTEM

RC-BX33SL

Area Suffix

UX---Saudi and relative U---Except ux

IMPORTANT

PLEASE TAKE NOTE BEFORE ORDERING

1. Order all service parts through JVC Asia Pte Ltd.- Customer Satisfaction Dept.

2. Two orders are available: Initial order and last order (Before End Of Line)

3. Minimum order quantity: 100pcs

4. Delivery term: Minimum 2 months upon confirmation of order.

Contents

Safety precautions ............................................................ 1-2

Preventing static electricity ...............................................1-3

Disassembly method .........................................................1-4

Adjustment method............................................................ 1-7

Description of major IC .................................................. 1-13



2001 JVC ASIA PTE LTD



No: 28208

DEC. 2001

RC-BX33SL

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 authorised 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 manufacturer’s 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, 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, tubing’s, 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 re-assembling.

5. Leakage current check (Electrical Shock hazard testing) After re-assembling 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 and 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, 1,000 ohms per volt or more sensitivity in the following manner. Connect a 1,500

0.15µF AC-type capacitor between an exposed 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.).

0.15µF AC TYPE

1500

XL-SV320SL/SV305GD

XL-SV308BU

10W resistor paralleled by a

AC Voltmeter (Having 1000 ohms/volts, or more sensitivity

Place this probe on each exposed

10W

metal part.

Good earth ground

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.

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

1-2

RC-BX33SL

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.

1.1. Grounding to prevent damage by static electricity

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

1.1.1. Ground the workbench

1. 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.

1.1.2. Ground yourself

1. 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 plate

1.1.3. Handling the optical pickup

1. 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.)

2. 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.

1.2. 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. It is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.

1-3

RC-BX33SL

Disassembly method

Removing the rear panel

From behind the body, remove the Five screws

retaining the rear panel.

Open the Battery door, then remove One Screw

retaining in the battery compartment

bottom side.

Then remove the Two screws

retaining the bottom of rear panel.

Take out the rear panel from the body. And disconnect the CN302 on the main board

right side.

Note:

Be careful of the FM antenna white wire, it is connection with the tuner PCB up side.

You can directly take out from the tuner PCB.

When you re-assembly the product, plug the FM antenna white wire into the Tuner

PCB'S "FM ANT" position.

Screw A.

Screw C.

Screw B.

1-4

RC-BX33SL

Removing the Main Board PCB (1)

Open & remove the rear panel

Remove the Two Screws

on the Black Backet,

then take out the black backet on the

front panel.

Screws D.

Remove the Two Screws

retaining on the

left of front panel.

Screws E.

Remove the One Screw

retaining on the

right of front panel.

Top panel

Screw F.

1-5

RC-BX33SL

Removing the Main Board PCB (2)

Disconnect the CN201, CN202 & C301 on the top of the

Main Board PCB.

Front Panel

CN 201

CN 202

Main PCB

CN 301

Top Panel

Then, take out the top panel from the front panel.

Remove the nine screws

from the Main Board PCB.

Screw G.

Take out the Main Board PCB from the front panel, & disconnect the CN901 & CN903

on the Main Board PCB.

1-6

RC-BX33SL

Adjustment method

Measurement instruments required for

Tuner section

adjustment

The input and output earth systems are separated.

1 Low frequency oscillator Reference measurement ----- 26.1mV(0.63/8)

This oscillator should have a capacity to output output 0dB to 600 at an oscillation frequency of Input positions ----- AM : Standard loop antenna 50Hz-20KHz FM : TP1 (hot) and TP2 (GND)

2 Electronic voltmeter 3 Distortion meter Precautions for measurement 4 Frequency counter 1 Direct connect to the IF sweeper output 5 Wow & flutter meter side and 1UF and 22 Kohm connect to the 6 Test tape sweeper input side. Same as FIG1.

TCC-112: Tape speed and running unevenness (3KHz) 1 U TCC-140: Reference level (1KHz) IC101 TP16 TCC-182A: Head angle (8KHz), playback frequency PIN18 22 K characteristics (1KHz) and dubbing frequency TP8 characteristics (125Hz and 8KHz)

7 Blank tape 2 The IF sweeper output level should be made as

TYPE I : TDK-D60 low as possible within the adjustable range.

3 Since the IF sweeper is a fixed device, there is

8 Torque gauge : For play and back tension no to adjust this sweeper.

FWD(CT-120m), and FF/REW(CT-F) 4 Since a ceramic oscillator is used, there is no

need to perform any MIX adjustment.

Measurement conditions 5 Since a fixed coil is used, there is no need to

adjustment the FM tracking. Power supply voltage -------------- AC120V (60Hz) 6 Reference output -------------- Speaker : 0.63V/8 In case of simultaneously measuring the voltage Headphone : 0.245V/32 in both of the input and output systmes with and

electronic voltmeter for two channels, therefore,

the earth should be connected particularly Input for confirming recording and ------- CD : -10dB carefully. playback characteristics 7 For connecting a dummy resistor when measuring Measurement output terminal ------- Speaker CN301 the output, use the wire with a greater code size. * Load resistance -------------------------------------- 8 8 Whenever any mixed tape is used, use the band

pass filter (DV-12V). Radio Input signal

AM frequency -------------------------------- 400Hz AM modulation ---------------------------------- 30% FM frequency --------------------------------- 1 KHz FM frequency deviation ------------------ 22.5KHz

1-7

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