Haier ht 3718 schematic

HT-3718

COLOUR TELEVISION

Service Manual

Model: HT-3718 (CYPRUS)

Features

218 programs stored Auto-correcting black balance Blue extension, Green improvement Multi-picture modes Fast teletext Audio/video input, S-Video input, SCART terminal

Haier Group

NO: M-EU-CY-HT-3718-9361 Edition:2003.5.20

CONTENTS

Contents

1 Contents

2 3 Features 4 Safety Precautions 5 Warning and Cautions 6 Net dimension 7 Parts and Functions 8 Remote Controller Functions 9 Program Diagram 10 Maintenance Service and Trouble shooting

Product Code illumination and Series Introduction

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4 5 11

11 Circuit Diagram 12 Circuit Explanation 13 Adjustment 14 Exploded View 15 List of Parts 16 Damageable Parts List 17 Information of Resistors and Capacitors

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18 22

Product Code illumination and Series Introduction

HT-3718

Color television appearance

CRT size(unit:inch)

Philip

haier

Functures

Features

NO.

ITEM

PICTURE

AUDIO

JACK

Main IC 9361

CRT

Color system

Audio system

NO.of channels

OSD language

Multi-picture modes

AV stereo

Super woofer

Surrounding sound

Treble/bass boost

Left/right balancer

NICAM

Multi-audio modes

Tone adjuster

MTS/SAP

Auto-volume leveling

AV input

AV output

DVD terminal

S-video jack

Headphone socket

SCART socket

FUNCTION

Flat square 25

ENGLISH 29

MODEL

NO.

HT-3718

PAL 26

B/G 27

218 28

back 1 41

back 1 42

ITEM

SOFTWARE

PARAMETER

FUNCTION

Digital curtain

Slow fading on & off

Semitransparent menu

Non-flashing channel changing

ZOOM

16:9 mode

Games

Calendar

Child-lock

Multi-functional lock

No-picture listening

Background light

Auto-timer on

CCD

V-CHIP

NO. of built-in speakers

Audio output power(W)

Total power input W

Voltage range V

Power frequency

Time of sleep timer(MINS)

Net weight(KG)

Gross weight(KG)

Net dimension(MM)

Packaged dimension(MM)

Quantity for 20' container

Quantity for 40' container

Quantiry for 40' high container

MODEL

HT-3718

~180-250

180

440×355×335

475×415×380

Safety Precautions

4.Safety Precautions

SAFETY PRECAUTIONS

IMPORTANT SAFETY NOTICE

Many electrical identify these parts and mechanical parts in this chassis have special safety-related characteristics! In the Schematic Diagram and Replacement Parts List.

It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent X-RADIATION, Shock, Fire, or other Hazards.

Do not modify the original design without permission of the manufacturer.

General Guidance

An Isolation Transformer should always be used during the servicing of a receiver whose chassis is not isolated from the AC power line. Use a transformer of adequate power rating as this protects the technician from accidents that might result in personal injury caused by electrical shocks.

It will also protect the receiver and it’s components from being damaged by accidental shorts of the circuitry that might be inadvertently introduced during the service operation.

If any fuse (or Fusible Resistor) in this TV receiver is blown, replace it with a specified one.

When replacing a high wattage resistor (Oxide Metal Film Resistor, over 1W), keep the resistor 10mm away from PCB.

Keep wires away from high voltage or high temperature parts.

Due to the high vacuum and large surface area of the picture tube, extreme care should be taken in handling the Picture Tube. Do not lift the Picture Tube by its Neck.

X-RAY Radiation

Warning:

The source of X-RAY RADIATION in this TV receiver is the High Voltage Section and the Picture Tube.

For continued X-RAY RADIATION protection, the replacement tube must be of the same type as specified in the Replacement Parts List.

Before returning the receiver to the customer,

Always perform an AC leakage current check on the exposed metallic parts of the cabinet, such as antennas, terminals, etc., to make sure that the set is safe to operate without any danger of electrical shock.

Warning and Cautions

5. Warning and Cautions

Warning and Cautions

1. When you clean the TV set, please pull out the power plu clean the cabinet and the screen with benzene, petrol and other chemicals.

In order to prolong the using life of the TV set, please place it on a ventilated place.

from AC outlet. Don't

4. To prevent the TV set from firing and electric shock, don't make the TV set rain or moisture.

5. Don't open the back cover, otherwise it is possible to damage the components in the TV set and harm you.

Don't place the

TV set in the sunshine or near heat source.

6. When the TV set isn't going to be used for long time or it is in thunder and lightening, please pull out the plug from AC outlet and the antenna plug from the cover of the TV set.

Explanation on the display tube

Generally, it is not needed to clean the tube surface. However, if necessary,its surface can be cleaned with a dry cotton cloth after cutting off the power.Don't use any cleanser. If using hard cloth, the tube surface will be damaged.

CAUTION:

Before servicing receivers covered by this service manual and its supplements and

addenda, read and follow the

NOTE:

If unforeseen circumstances create conflict between the following servicing precautions

SAFETY PRECAUTIONS

Warning and Cautions

and any of the safety precautions, always follow the safety precautions. Remember: Safety First.

General Servicing Precautions

5.1 Always unplug the receiver AC power cord from the AC power source before:

a. Removing or reinstalling any component, circuit board module or any other assembly of

the receiver.

b. Disconnecting or reconnecting any receiver electrical plug or other electrical connection.

c. Connecting a test substitute in parallel with an electrolytic capacitor in the receiver.

CAUTION: A wrong substitution part or incorrect installation polarity of electrolytic

capacitors may result in an explosion hazard.

d. Discharging the picture tube anode.

5.2 Test high voltage only by measuring it with an appropriate high voltage meter or other voltage-measuring device (DVM, FETVOM, etc.) equipped with a suitable high voltage probe. Do not test high voltage by “drawing an arc”.

5.3 Discharge the picture tube anode only by (a) first connecting one end of an insulated clip lead to the degaussing or kine aquadag grounding system shield at the point where the picture tube socket ground lead is connected, and then (b) touch the other end of the insulated clip lead to the picture tube anode button, using an insulating handle to avoid personal contact with high voltage.

5.4 Do not spray chemicals on or near this receiver or any of its assemblies.

5.5 Unless specified otherwise in this service manual, clean electrical contacts only by applying

the following mixture to the contacts with a pipe cleaner, cotton-tipped stick or comparable nonabrasive applicator; 10% (by volume) Acetone and 90% (by volume) isopropyl alcohol (90%-99% strength)

CAUTION: This is a flammable mixture.

Unless specified otherwise in this service manual, lubrication of contacts is not required.

5.6 Do not defeat any plug / socket B+ voltage interlocks with which receivers covered by this

service manual might be equipped.

5.7 Do not apply AC power to this instrument and/or any of its electrical assemblies unless all

solid-state device heat sinks are correctly installed.

5.8 Always connect the test receiver ground lead to the receiver chassis ground before

connecting the test receiver positive lead.

Always remove the test receiver ground lead last.

5.9 Use with this receiver only the test fixtures specified in this service manual.

CAUTION: Do not connect the test fixture ground strap to any heat sink in this receiver.

Warning and Cautions

Electrostatic ally Sensitive (ES) Devices

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components are usually called Electrostatic ally Sensitive (ES) Devices. Examples of typical ES

Warning and Cautions

devices are integrated circuits and some field effect transistors and semiconductor “chip” components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity.

a. Immediately before handling any semiconductor component or semiconductor- equipped assembly, drain off any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging wrist strap device, which should be removed to prevent potential shock prior to applying power to the unit under test.

b. After removing an electrical assembly equipped with ES devices, place the assembly on a

conductive surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.

c. Use only a grounded-tip soldering iron to solder or unsolder ES devices.

d. Use only an anti-static type folder removal device. Some solder removal devices not

classified as “anti-static” can generate electrical charges sufficient to damage ES devices.

e. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to

damage ES devices.

f. Do not remove a replacement ES device from its protective package until immediately before

you are ready to install it. (Most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or comparable conductive material).

g. Immediately before removing the protective material from the leads of a replacement ES

device, touch the protective material to the chassis or circuit assembly into which the device will be installed.

CAUTION: Be sure no power is applied to the chassis or circuit, and observe all other safety

precautions.

h. Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise

even some normally harmless motions such as mutual brushing of your clothes’ fabric or lifting of your foot from a carpeted floor might generate static electricity sufficient to damage an ES device.)

General Soldering Guidelines

a. Use a grounded-tip, low-wattage soldering iron and appropriate tip size and shape that will maintain tip temperature within the range of 500 oF to 600 oF.

b. Use an appropriate gauge of RMA resin-core solder composed of 60 parts tin/40 parts lead.

c. Keep the soldering iron tip clean and well tinned.

d. Thoroughly clean the surfaces to be soldered. Use a mall wire bristle (0.5 inch, or 1.25cm)

brush with a metal handle. Do not use freon-propelled spay-on cleaners.

e. Use the following unsoldering technique

a). Allow the soldering iron tip to reach normal temperature. (500 o F to 600o F)

b). Heating the component lead until the solder melts.

Warning and Cautions

a. draw the melted solder with an anti-static, suction-type solder removal device with solder

braid.

CAUTION: Work quickly to avoid overheating the circuit board printed foil.

f. Use the following unsoldering technique

A). Allow the soldering iron tip to reach normal temperature. (500 o F to 600o F)

B). First, hold the soldering iron tip and solder the strand against the component lead until the solder melts.

C). Quickly move the soldering iron tip to the junction of the component lead and the printed circuit foil, and hold it there only until the solder flows onto and around both the component lead and the foil.

CAUTION: Work quickly to avoid overheating the circuit board printed foil.

D). Closely inspect the solder area and remove any excess or splashed solder with a small wire-bristle brush.

Remove /Replacement

Some chassis circuit boards have slotted holes (oblong) through which the IC leads are inserted and then bent flat against the circuit foil. When holes are of slotted type, the following technique should be used to remove and replace the IC. When working with boards using the familiar round hole, use the standard technique as outlined.

Removal

Desolder and straighten each IC lead in one operation by gently prying up on the lead with the soldering iron tip as the solder melts.

Draw away the melted solder with an anti-static suction-type solder removal device (or with solder braid) before removing the IC.

Replacement

Carefully insert the replacement IC in the circuit board.

Carefully bend each IC lead against the circuit foil pad and solder it.

Clean the soldered areas with a small wire-bristle brush. (It is not necessary to reapply acrylic coating to the areas).

“Small-Signal” Discrete Transistor Removal/Replacement

Remove the defective transistor by clipping its leads as close as possible to the component body.

Bend into a “U” shape the end of each of three leads remaining on the circuit board.

Bend into a “U” shape the replacement transistor leads.

Connect the replacement transistor leads to the corresponding leads extending from the circuit board and crimp the “U” with long nose pliers to insure metal to metal contact then solder each connection.

Power Output, Transistor Device

Warning and Cautions

Removal/Replacement

Heat and remove all solder from around the transistor leads.

Remove the heat sink mounting screw (if so equipped).

Carefully remove the transistor from the heat sink of the circuit board.

Insert new transistor in the circuit board.

Solder each transistor lead, and clip off excess lead.

Replace heat sink.

Diode Removal/Replacement

Remove defective diode by clipping its leads as close as possible to diode body.

Bend the two remaining leads perpendicularly to the circuit board.

Observing diode polarity, wrap each lead of the new diode round the corresponding lead on the circuit board.

Securely crimp each connection and solder it.

Inspect (on the circuit board copper side) the solder joints of the two “original” leads. If they are not shiny, reheat them and if necessary, apply additional solder.

Fuse and Conventional Resistor Removal/Replacement

a. Clip each fuse or resistor lead at top of the circuit board hollow stake.

b. Securely crimp the leads of replacement component around notch at stake top.

c. Solder the connections

CAUTION: Maintain original spacing between the replaced component and adjacent

components and the circuit board to prevent excessive component temperatures.

Circuit Board Foil Repair

Excessive heat applied to the copper foil of any printed circuit board will weaken the adhesive that bonds foil to the circuit board causing the foil to separate from or “lift-off” the board. The following guidelines and procedures should be followed whenever this condition is encountered.

At IC Connections

To repair a defective copper pattern at IC connections use the following procedure to install a jumper wire on the copper pattern side of the circuit board. (Use this technique only on IC connections).

a. Carefully remove the damaged copper pattern with a sharp knife. (Remove only as much

copper as absolutely necessary).

b. Carefully scratch away the solder resist and acrylic coating (if used) from the end of the

remaining copper pattern.

c. Bend a small “U” in one end of a small gauge jumper wire and carefully crimp it around the IC

Warning and Cautions

pin. Solder the IC connection.

d. Route the jumper wire along the path of the out-away copper pattern and let it overlap the

previously scraped end of the good copper pattern. Solder the overlapped area and clip off any excess jumper wire.

At other connections

Use the following technique to repair the defective copper pattern at connections other than IC Pins. This technique involves the installation of a jumper wire on the component side of the circuit board.

a. Remove the defective copper pattern with a sharp knife.

Remove at least 1/4 inch of copper, to insure that a hazardous condition will not exist if the jumper wire opens.

b. Trace along the copper pattern from both sides of the pattern break and locate the nearest

component that is directly connected to the affected copper pattern.

c. Connect insulated 20-gauge jumper wire from the lead of the nearest component on one side of

the pattern break to the lead of the nearest component on the other side.

Carefully crimp and solder the connections.

CAUTION: Be sure the insulated jumper wire is dressed so that it does not touch components or

sharp edges.

Net dimension

Top-view

Net dimension

Side view

Front view

HT-3718

Parts and Functions

FUNCTION BUTTONS AND EXTERNAL SOCKETS

1.Front Panel

Parts and Functions

Remote sensor:let The remote controller aim here the set can receive remote

control signal.

Power switch:Press the button to turn on the TV set . press the button again to turn

off the TV set.

Power indicator: the indicator lights when po wer on . Menu butto n program up/down button Volu me up/down button TV/AV

Audio (R) input Audio (L) input Video input

2.Rear Panel

１１

S-VIDEO input

１２

SCART socket

１３

Antenna input

Ｓ－ＶＩＤＥＯＳＣＡＲＴ

１３

１１

１２

Remote Controller Functions

Remote Controller

REM OTE CONTROLLER BOARD

MARK FUNCTION DESCRIPTION

Program scan Standby

SW A P

Mute

TV /AV

-VOL+

-C H +

SOUND TIM E

FUNCTION

0-9

-/--

TV /VID EO SE L E CTIO N VOLUM E CONTROL CHANNEL NUM BER UP/DOW N PICTUR E MENU

SOUND MENU TIM E MENU

FUNCTION MENU

ONE DIGIT SE LECTIO N

MENU DISPLAY EXIT M ENU DISP LAY

A2 /NICAM /MONO SOUND SELECTION PICTU RE M ODE SEL E CT ION

NO US ED TUNE M ENU SELECTI ON

TELETEX T SU B TIT LE

TV /TEL ETEX T ENTERING/EXITING TO REVEAL CONCEALED TELET EX T TELETE X T ZOO M

TELETEXT P AGE HOLD TELETEXT/TV MIX MO DE

TV /TEL ETEX T A LTERA TIO N

NOTE

EA ST/W EST

The function of selecting m enu but t on on t he rem ote controller is th e sam e as th a t of program up/dow n button on th e TV s et. The fuct i on of ident i fyi ng m enu but t on o n th e re m o te co n tro lle r is th e sam e as th at of volum e up/dow n but ton on t he TV s et.

Program Diagram

Insert the power plug into the power line socket and insert the antenna plug into the antenna socket on the rear panel. Press down the power switch of the TV set. The red indicator light goes on. If no picture appears, press the button on the remote controller. Follow the steps below.

A Program preset

1. Auto searching and storing program

Press MENU button on the remote controller then use the “CH+/CH-“ key to call up the “tune program” menu on the screen. Then Press the menu” VOL+/VOL- “ item to adjust. it.Use the “CH+/CH- ” key to select the bar “auto search program” then press the “VOL+/VOL-” to make sure. If you want to stop ,press the key “ MENU ”.

2. Manual search and fine tune

Press MENU button then use the “CH+/CH-“ key to call up the “tune program” menu on the screen. Then Press the menu” VOL+/VOL- “ item to adjust. it.Use the “CH+/CH-” key to select the bar “Manual search program” then press the “VOL+/VOL-” to make sure.

3.Deleting channel number

Press Program up/down buttons to select a channel to skip. Press MENU to call Menu. then use the “CH+/CH- “ key to call up the “tune program” menu on the screen. Then Press the menu” VOL+/VOL- “ item to adjust. it.Use the “CH+/CH-” key to select the bar “Cannal number” then press the “VOL+/VOL-” to make sure. Enter the number that you do not want to see .Then Then select “SKIP” and select SKIP to ON. Now the program number is deleted. Repeat the above steps and select SKIP to OFF, the deleted program number can be resumed.

B Volume tuning

Press VOLUME buttons VOL+ to increase and VOL- to decrease the volume.

C Personal preference settings

Picture modes

Press SELC PICTURE repeatedly to change among MEMORY 1, MEMORY2,MEMORY3,to chang

the Picture Mode.

+ 32 hidden pages

Haier ht 3718 schematic

Specifications and Main Features

Frequently Asked Questions

User Manual