JVC TU-HD500A Service Manual

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Page 1

SERVICE MANUAL

HD DIGITAL TERRESTRIAL SET TOP BOX

YA22720051

TU-HD500A

STB

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

No.YA227

2005/1

Page 2

SPECIFICATION

Items Contents

Dimensions ( W × H × D ) 34.0cm × 7.0cm × 27.0cm

Mass (approx.) 2.6kg

Broadcasting System (Terrestrial) DVB-T / OFDM

RF System PAL

Video System PAL

Audio System (Digital) MPEG-1 layers 1 / 2 , MPEG-2 layers 2 , 32kHz / 44.1kHz / 48kHz

Teletext System Digital Teletext

Receiving Frequency VHF 174MHz to 230MHz

UHF 520MHz to 820MHz

Power Input AC100V to AC250V, 50Hz / 60Hz

Power Consumption 40W(Max) / 25W(Nominal) / 3W(standby)

Antenna Input (U/V Input) 75Ω, (PAL type) x1, IEC-Female connector Loop Output (U/V Output) 75Ω, (PAL type) x1, IEC-Male connector

TV Output Composite Video

S-Video

SD Output Component Video

RGB Video

HD Output 1080i/720p/576p Video Y : 1V(p-p), 75Ω

HD VGA Output

Analog Audio Output 2.0V(rms), 10KΩ, stereo (RCA x2) Digital Audio Output S/PDIF coaxial (RCA) × 1, S/PDIF optical (TOS Link) × 1 Remote Control Unit GTR300RBAJ10 (RM-C1050), (AA/R06 dry battery × 2)

1V(p-p) , 75Ω Y : 1V(p-p) positive, 75Ω C : 0.286V(p-p) (burst signal), 75Ω

Y/GS : 1V(p-p) , 75Ω PB/B / PR/R : 0.7V(p-p) , 75Ω 1V(p-p) , 75Ω

PB / PR :0.7V(p-p), 75Ω

D-SUB 15-pin

RGB

0.7V(p-p) ,75Ω

VGA

640dot × 480dot

Design & specifications are subject to change without notice.

1-2 (No.YA227)

Page 3

SECTION 1

PRECAUTION

1.1 SAFETY PRECAUTIONS

(1) The design of this product contains special hardware,

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 products 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 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 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) Don't short between the LIVE side ground and

ISOLATED (NEUTRAL) side ground or EARTH side ground when repairing.

Some model's power circuit is partly different in the GND. The difference of the GND is shown by the LIVE : ( ) side GND, the ISOLATED (NEUTRAL) : ( ) side GND and EARTH : ( ) side GND. Don't short between the LIVE side GND and ISOLATED (NEUTRAL) side GND or EARTH side GND and never measure the LIVE side GND and ISOLATED (NEUTRAL) side GND or EARTH side GND at the same time with a measuring apparatus (oscilloscope etc.). If above note will not be kept, a fuse or any parts will be broken.

(5) If any repair has been made to the chassis, it is

recommended that the B1 setting should be checked or adjusted (See B1 POWER SUPPLY check).

(6) The high voltage applied to the picture tube must conform

with that specified in Service manual. Excessive high voltage can cause an increase in X-Ray emission, arcing and possible component damage, therefore operation under excessive high voltage conditions should be kept to a minimum, or should be prevented. If severe arcing occurs, remove the AC power immediately and determine the cause by visual inspection (incorrect installation, cracked or melted high voltage harness, poor soldering, etc.). To maintain the proper minimum level of soft X-Ray emission, components in the high voltage circuitry including the picture tube must be the exact replacements or alternatives approved by the manufacturer of the complete product.

(7) Do not check high voltage by drawing an arc. Use a high

voltage meter or a high voltage probe with a VTVM. Discharge the picture tube before attempting meter connection, by connecting a clip lead to the ground frame

and connecting the other end of the lead through a 10kΩ

2W resistor to the anode button.

(8) When service is required, observe the original lead dress.

Extra precaution should be given to assure correct lead dress in the high voltage circuit area. Where a short circuit has occurred, those components that indicate evidence of overheating should be replaced. Always use the manufacturer's replacement components.

(9) Isolation Check (Safety for Electrical Shock Hazard)

After re-assembling the product, always perform an isolation check on the exposed metal parts of the cabinet (antenna terminals, video/audio input and output terminals, Control knobs, metal cabinet, screw heads, earphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.

a) Dielectric Strength Test

The isolation between the AC primary circuit and all metal parts exposed to the user, particularly any exposed metal part having a return path to the chassis should withstand a voltage of 3000V AC (r.m.s.) for a period of one second. (. . . . Withstand a voltage of 1100V AC (r.m.s.) to an appliance rated up to 120V, and 3000V AC (r.m.s.) to an appliance rated 200V or more, for a period of one second.) This method of test requires a test equipment not generally found in the service trade.

b) Leakage Current Check

Plug the AC line cord directly into the AC outlet (do not use a line isolation transformer during this check.). Using a "Leakage Current Tester", measure the leakage current from each exposed metal part of the cabinet, particularly any exposed metal part having a return path to the chassis, to a known good earth ground (water pipe, etc.). Any leakage current must not exceed 0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.2mA AC (r.m.s.).

Alternate Check Method

Plug the AC line cord directly into the AC outlet (do not use a line isolation transformer during this check.). Use

an AC voltmeter having 1000Ω per volt or more sensitivity in the following manner. Connect a 1500Ω 10W resistor paralleled by a 0.15µF AC-type capacitor

between an exposed metal part and a known good earth ground (water pipe, etc.). 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. Any voltage measured must not exceed 0.75V AC (r.m.s.). This corresponds to

0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.3V AC (r.m.s.). This corresponds to 0.2mA AC (r.m.s.).

AC VOLTMETER (HAVING 1000 /V, OR MORE SENSITIVITY)

0.15 F AC-TYPE

PLACE THIS PROBE

1500 10W

GOOD EARTH GROUND

ON EACH EXPOSED ME TAL PAR T

(No.YA227)1-3

Page 4

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 INTRODUCTION

• TU-HD500A 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-HD500A also has digital audio output.

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

2.2 FUNCTIONS

[REMOTE CONTROL UNIT]

1. POWER

Turn your HD-STB on or off.

2. 0-9 (Number)

Direct change the desired channel.

3. SLEEP

Press to adjustment the period of off time.

15min 30min 45min 60min 90min

Off 240min 180min 120min

4. FAV (Favorite)

Direct change the Favorite CH in the menu.

All Fav1 Fav2 Fav3

5. QUICK CH (Quick channel)

To quick memorized channel change.

6. EXIT

Quit the menu system.

7. LIST

Display the selected memorized channel list followed by Favorite CH select. You can direct select desired channel using CH [/], PR [/ ] button.

8. CH [/] (Up/Down)

Change the channel Up or Down followed by memorized channel.

9. INFO (Information)

Display current channel EPG information. You can see the NOW and NEXT information. If you press INFO button again, you can see the more detailed information.

10. ENTER

Select the current setting in the menu system.

11. PR [/] (Left / Right)

Change the program up or down. In the menu system, move left or the cursor.

12. PREV (Previous channel)

Direct go to the previous watched channel.

13. MENU

Activate the menu system.

14. FREEZE

Freezing the picture for viewing with still image. Sound muting is also activated.

15. WIDE

To picture aspect ratio change. It will change to 4:3PS 4:3LB 16:9 4:3PS. (4:3 PS : 4:3 Pan and Scan / 4:3 LB : 4:3 Letter Box)

16. S.TITLE (Sub title)

Activate Sub title (Caption) display On / Off.

17. MUTE

Activate audio output muting for set-top box.

 TV CONTROL SECTION

18. MUTE (Picture muting)

Activate Picture muting operation.

19. TV CH [/]

Change the TV analog channel Up or Down.

20. TV/AV (External Video Input Select)

Select the TV external video input.

21. TV VOL [/]

Change the TV Volume level Up or Down.

22. TV POWER

Turn On / Off the TV set.

1-4 (No.YA227)

Page 5

[FRONT]

1 2 3 4 5 6 78

1. POWER

Press to turn the HD-STB on or off.

2. Display panel

Display information to assist you in operating the HD-STB successfully.

3. MENU

Activate the menu system.

4. EXIT

Quit the menu system.

5. ENTER

Select the items in the menu system.

[REAR]

9 11 12

2122

17 1819

6. PROGRAM (Up / Down)

"Press to change the program (This action changes the programs stored in the favorite channels memory blocks)." "Left or Right movement in the menu system."

7. CHANNEL (Up / Down)

"Press to change the channels (This action changes the memorized channels in sequence)." "Up or Down movement in the menu system."

8. Remote sensor

This HD-STB receives infrared remote signal from your remote control. Do not block it.

141516

9. ANT IN terminal

Attach an external Antenna to this terminal.

10. LOOP OUT terminal

Use this terminal to feed RF signal to your TV or VCR for analog reception.

11. TV composite video output terminal

Use this terminal with your TV video input.

12. S-VIDEO output terminal

Use this terminal with your TV S-video input.

13. AUDIO 1 output terminal (L/R analog stereo)

This terminal can be used with your TV analog audio input.

14. SD Y/Pb/Pr or SD RGB (SD component video) Output terminal

Use this terminal with your TV equipped with component video input. (SD or Normal)

15. HD Y/Pb/Pr (HD component video) output terminal

Use this terminal with your TV HD Component video input. (HDTV only)

16. AUDIO 2 output terminal (L/R analog stereo)

This terminal can be used with your TV analog audio input.

17. Optical DIGITAL AUDIO (S/P DIF) output terminal

Use this terminal with A/V device equipped with optical digital input.

18. Coaxial DIGITAL AUDIO (S/P DIF) output terminal

Use this terminal with A/V device equipped with coaxial digital input.

19. HD VGA (HD component R.G.B/H.V) output terminal

Use this terminal with your TV HD VGA Video input. (only HDTV equipped with VGA input or computer monitor).

20. MODE select switch

Set this switch in conjunction with DISPLAY switch according to your TV display capability.

21. DISPLAY select switch

Set this switch in conjunction with MODE switch according to your TV display capability.

22. RS-232C [Do not use]

Use this terminal for software upgrade purpose only.

23. Power cord

(No.YA227)1-5

Page 6

SECTION 3

DISASSEMBLY

3.1 DISASSEMBLY PROCEDURE

NOTE:

• Make sure that the power cord is disconnected from the outlet.

• Pay special attention not to break or damage the parts.

• When removing each board, remove the connectors as required. Taking notes of the connecting points (connector numbers)

makes service procedure manageable.

• Make sure that there is no bent or stain on the connectors before inserting, and firmly insert the connectors.

3.1.1 REMOVING THE TOP COVER

(1) Remove the 5 screws [A]. (2) Slightly spread the bottom of the TOP COVER. (3) Shift the TOP COVER rearward and raise it upward to

remove it.

3.1.2 REMOVING THE FRONT PANEL / KNOBS

• Remove the TOP COVER.

• Remove the FLAT CABLE. (1) Remove the 2 screws [B]. (2) Remove the 2 claws [C]. (3) Remove the FRONT PANEL. (4) Remove the KNOBS.

• Pay special attention : Refer to ATTACHMENT CAUTION FOR KNOBS.

3.1.3 REMOVING THE FRONT PWB

• Remove the TOP COVER. (1) Remove the 5 screws [D]. (2) Remove the FRONT PWB.

3.1.4 REMOVING THE REAR PANEL

• Remove the TOP COVER. (1) Remove the 3 screws [E]. (2) Withdraw the REAR PANEL back ward. (3) Remove the REAR PANEL.

3.1.7 CHECKING THE PW BOARD

• To check the back side of the PW Board. (1) Pull out the PW Board. (Refer to REMOVING THE MAIN

PWB).

(2) Erect the PW Board vertically so that you can easily check

the back side of the PW Board.

CAUTION:

• When erecting the PW Board, be careful so that there will be

no contacting with other PW Board.

• Before turning on power, make sure that the wire connector

is properly connected.

3.1.8 WIRE CLAMPING AND CABLE TYING

(1) Be sure to clamp the wire. (2) Never remove the cable tie used for tying the wires

together. Should it be inadvertently removed, be sure to tie the wires with a new cable tie.

ATTACHMENT CAUTION FOR KONBS

FRONT PANEL

3.1.5 REMOVING THE MAIN PWB

• Remove the TOP COVER.

• Remove the REAR PANEL. (1) Remove the 2 screws [F]. (2) Remove the MAIN PWB.

CAUTION:

If necessary, take off the wire clamp, connectors etc. Be careful enough when developing a MAIN PWB.

3.1.6 REMOVING THE POWER PWB

• Remove the TOP COVER.

• Remove the connector of the POWER CORD. (1) Remove the 4 screws [G]. (2) Remove the POWER PWB. (3) Remove the INSULATOR.

1-6 (No.YA227)

KNOB

( / / / )

Width : Narrow

Width : Wide

KNOB

(MENU/EXIT/ENTER)

Width : Wide

Page 7

TOP COVER

(x1)

(x3)

(x4)

POWER PWB

(x2)

See before page

MAIN PWB

(x2)

INSULATOR

FRONT PANEL

(x2)

KNOB

FRONT PWB

FRONT

FRONT PLATE

INSULATOR

POWER CORD

GASKET

(x5)

(x3)

BOTTOM COVER

REAR PANEL

(No.YA227)1-7

Page 8

3.2 REPLACEMENT OF CHIP COMPONENT

3.2.1 CAUTIONS

(1) Avoid heating for more than 3 seconds. (2) Do not rub the electrodes and the resist parts of the pattern. (3) When removing a chip part, melt the solder adequately. (4) Do not reuse a chip part after removing it.

3.2.2 SOLDERING IRON

(1) Use a high insulation soldering iron with a thin pointed end of it. (2) A 30w soldering iron is recommended for easily removing parts.

3.2.3 REPLACEMENT STEPS

1. How to remove Chip parts

2. How to install Chip parts

[Resistors, capacitors, etc.]

(1) As shown in the figure, push the part with tweezers and

alternately melt the solder at each end.

(2) Shift with the tweezers and remove the chip part.

[Transistors, diodes, variable resistors, etc.]

(1) Apply extra solder to each lead.

SOLDER

[Resistors, capacitors, etc.]

(1) Apply solder to the pattern as indicated in the figure.

(2) Grasp the chip part with tweezers and place it on the

solder. Then heat and melt the solder at both ends of the chip part.

[Transistors, diodes, variable resistors, etc.]

(1) Apply solder to the pattern as indicated in the figure. (2) Grasp the chip part with tweezers and place it on the

solder.

(3) First solder lead A as indicated in the figure.

(2) As shown in the figure, push the part with tweezers and

alternately melt the solder at each lead. Shift and remove the chip part.

NOTE :

After removing the part, remove remaining solder from the pattern.

1-8 (No.YA227)

(4) Then solder leads B and C.

Page 9

SECTION 4

ADJUSTMENT

This service manual does not describe ADJUSTMENT.

(No.YA227)1-9

Page 10

SECTION 5

TROUBLESHOOTING

This service manual does not describe TROUBLESHOOTING.

1-10 (No.YA227)

Page 11

Victor Company of Japan, Limited AV & MULTIMEDIA COMPANY VIDEO DISPLAY CATEGORY 12, 3-chome, Moriya-cho, kanagawa-ku, Yokohama, kanagawa-prefecture, 221-8528, Japan

(No.YA227)

Printed in Japan

VPT