JVC TU-DB1SK Service Manual

YA211200411

SERVICE MANUAL

DIGITAL TERRESTRIAL SET TOP BOX

TU-DB1SK

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TABLE OF CONTENTS

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

2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

COPYRIGHT © 2004 Victor Company of Japan, Limited

No.YA211

2004/11

SPECIFICATION

Items Contents

Dimensions ( W × H × D ) 28.0cm × 4.0cm × 18.5cm

Mass 1.3kg

Broadcasting System DVB-T 2k & 8k

RF System PAL

Video System PAL

Audio System MPEG Layer I & II , 32kHz / 44.1kHz / 48kHz , Single / Dual channels , Stereo & joint stereo

Teletext System Digital Teletext

Channel Memory Number 200ch

Channel Coverage 474MHz to 858MHz

Power Requirements DC6V, AC adaptor : AC100V to AC240V, 50Hz / 60Hz

Antenna Input 75Ω unbalanced, PAL type × 1 (5V DC active antenna supply)
TV Output 75Ω unbalanced, PAL type × 1 (Loop through)

Video 1V (p-p) , 75Ω

TV(SCART-1)
Terminal
(Input/Output)

VCR(SCART-2)
Terminal
(Input/Output)

Digital Audio Output SPDIF coaxial × 1
Remote Control Unit VE-30031949 (RM-C1890S), (AA/R06 dry battery × 2)

Design & specifications are subject to change without notice.

Audio 500mV (rms) (-4dBs), 10kΩ min

RGB / Video 1V (p-p) , 75Ω

S-Video

RGB / Video 1V (p-p) , 75Ω

S-Video

Y : 1V (p-p) positive, 75Ω

C : 0.286V (p-p) (burst signal), 75Ω
Video 1V (p-p) , 75Ω
Audio 500mV (rms) (-4dBs), 10kΩ min

Y : 1V (p-p) positive, 75Ω

C : 0.286V (p-p) (burst signal), 75Ω

1-2 (No.YA211)

SECTION 1

PRECAUTION

1.1 SAFETY PRECAUTIONS

(1) The 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. Service should be performed by qualified personnel
only.

(2) Alterations of the design or circuitry of the product should not be made. Any design alterations or additions will void the

manufacturer's warranty and will further relieve the manufacturer of responsibility for personal injury or property damage
resulting therefrom.

(3) Many electrical and mechanical parts in the product have special safety-related characteristics. These characteristics are often

not evident from visual inspection nor can the protection afforded by them necessary 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 part shown in the Parts List of Service Manual may cause 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.

WARNING

(1) The 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.

(No.YA211)1-3

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 INTRODUCTION

• TU-DB1SK is a DVB-T set-top box capable of decoding MPEG coded source. It outputs CVBS, RGB and Y/C analog video and left

-right analog audio. TU-DB1SK also has digital audio output.

• The tuner is capable of getting both digital broadcasts. The tuner is capable of receiving both UHF horizontal band.
The tuning is available through the digitally controlled I2C bus (PLL).

2.2 FUNCTIONS

[FRONT]

[REAR]

1

3 4

2

5

1 Standby button(Power)
2 Power Indicator
3 Program up button
4 Program down button
5 REMOTE CONTROL UNIT Sensor

RS 232 TV OUT ANTENNA TV VCR SPDIF 6V DC

1

3

2

4

5 6 7

1-4 (No.YA211)

1 RS 232 Terminal
2 TV Output
3 Antenna Terminal
4 TV (Scart-1) Terminal (21-pin Euro connector)
5 VCR (Scart-2) Terminal (21-pin Euro conector)
6 SPDIF Terminal
7 DC 6V Input Terminal