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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-----------------------------------------------------------------------1

2 Product Code illumination and Series Introduction----------------------2

3 Features----------------------------------------------------------------------------------3

4 Safety Precautions--------------------------------------------------------------------4

5 Warning and Cautions---------------------------------------------------------------5

6 Net dimension--------------------------------------------------------------------------11

7 Parts and Functions------------------------------------------------------------------12

8 Remote Controller Functions-----------------------------------------------------13

9 Program Diagram----------------------------------------------------------------------14

10 Maintenance Service and Trouble shooting----------------------------------15

11 Circuit Diagram-------------------------------------------------------------------------18

12 Circuit Explanation--------------------------------------------------------------------22

13 Adjustment-------------------------------------------------------------------------------27

14 Exploded View--------------------------------------------------------------------------28

15 List of Parts------------------------------------------------------------------------------29

16 Damageable Parts List---------------------------------------------------------------44

17 Information of Resistors and Capacitors--------------------------------------45




1
Product Code illumination and Series Introduction


2.Product Code illumination and Series Introduction



HT-3718
Color television appearance

CRT size(unit:inch)


Philip

haier




2
Functures


1. Features
NO. MODEL
MODEL
ITEM FUNCTION NO. ITEM FUNCTION
HT-3718 HT-3718
1 PICTURE Main IC 9361 24 SOFTWARE Digital curtain
2 CRT Flat square 25 Slow fading on & off
3 Color system PAL 26 Semitransparent menu
4 Audio system B/G 27 Non-flashing channel changing
5 NO.of channels 218 28 ZOOM
6 OSD language ENGLISH 29 16:9 mode
7 Multi-picture modes 30 Games
8 AUDIO AV stereo 31 Calendar
9 Super woofer 32 Child-lock
10 Surrounding sound 33 Multi-functional lock
11 Treble/bass boost 34 No-picture listening
12 Left/right balancer 35 Background light
13 NICAM 36 Auto-timer on
14 Multi-audio modes 37 CCD
15 Tone adjuster 38 V-CHIP
16 MTS/SAP 39 PARAMETER NO. of built-in speakers 2
17 Auto-volume leveling 40 Audio output power(W) 3
18 JACK AV input back 1 41 Total power input W 70
19 AV output back 1 42 Voltage range V ~180-250
20 DVD terminal 43 Power frequency Hz 50
21 S-video jack 44 Time of sleep timer(MINS) 180
22 Headphone socket 45 Net weight(KG) 11
23 SCART socket 46 Gross weight(KG) 12
47 Net dimension(MM) 440×355×335
48 Packaged dimension(MM) 475×415×380
49 Quantity for 20' container
50 Quantity for 40' container
51 Quantiry for 40' high container




3
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.




4
Warning and Cautions

5. Warning and Cautions
Warning and Cautions

1. When you clean the TV set, please pull 4. To prevent the TV set from firing and
out the power plug from AC outlet. Don't electric shock, don't
clean the cabinet and the screen with make the TV set rain
benzene, petrol and other chemicals. or moisture.




2. In order to prolong the using life of the 5. Don't open the back cover, otherwise it is
TV set, please place it on a ventilated possible to damage the components in the
place. TV set and harm you.




3. Don't place the 6. When the TV set isn't going to be used
TV set in t h e for long time or it is in thunder and
sunshine or near lightening, please pull out the plug from AC
heat source. 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 SAFETY PRECAUTIONS.
NOTE: If unforeseen circumstances create conflict between the following servicing precautions
5
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 Warning and Cautions
this receiver.
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
6
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.

7
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
8
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


9
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.




10
Net dimension


6. Net dimension




Top-view




Side view




Front view




HT-3718




11
Parts and Functions


7. Parts and Functions

FUNCTION BUTTONS AND EXTERNAL SOCKETS
1.Front Panel




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 power on .
Menu button
program up/down button
Volume up/down button
TV/AV
Audio (R) input
Audio (L) input
Video input

2.Rear Panel




S-VIDEO input
SCART socket
Antenna input




12
Remote Controller Functions


8. Remote Controller Functions

Remote Controller
R EM O TE C O N TR O LLER BO A R D
M A RK FU N C T IO N D E SC R IPTIO N
Program scan
Standby
SW A P
M ute
1 2 3




TV / AV TV / ID E O SE LE C TIO N
V
-V O L + V O L U M E C O N TR O L
-C H + C H A N N E L N U M B E R U P/ O W N
D
PIC TU R E M E N U
SO U N D SO U N D M E N U
P
P.




PIC TU R E
TIM E TIM E M E N U
FUNCTI ON FU N C TIO N M EN U
0-9 O N E D IG IT SE LE C TIO N
?
-/--
M E N U M E N U D ISPL A Y
EX IT M EN U D ISPL A Y
A 2/ IC A M / O N O SO U N D SEL EC T IO N
N M
PIC TU R E M O D E SE LE C TIO N
N O U SE D
T U N E M EN U SEL E C T IO N
T E L E T E X T S U B T IT L E
TV / EL ETE X T E N TE R IN G / X ITIN G
T E
TO R EV EA L C O N C E A LE D TEL ET EX T
TE LE TE X T ZO O M
T E L E T E X T PA G E H O L D
T E L E T E X T /T V M IX M O D E
TV / EL ETE X T A LTER A TIO N
T

EA ST/ E ST
W
N O TE
i ect ng t
T he funct on of sel i m enu but on on t rem ot cont l i
he e rol er s
t sam e as t of program up/
he hat dow n but on on t T V set
t he .
T he fuct on of i
i i ng t
dent fyi m enu but on on t rem ot cont l
he e rol er
i t sam e as t of vol e up/
s he hat um dow n but on on t TV set
t he .




13
Program Diagram



9. 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.




14
Maintenance Service and Trouble shooting


10. Maintenance Service and Trouble shooting

a.Factory adjustment information

Operation method: after the appliance is switched on, press MUTE CALL -/-- CALL MUTE

Button in turn and enter service mode.

Press PRO- and PRO+ buttons to select items for adjustment.

Press VOL- and VOL+ buttons to adjust selected items.

Press the POWER button to switch off the appliance and go back to the normal state.

Maintenance menu (Table 8)


Variable
Item Specifications Default Value
Mark
5PAR Horizontal parabola *
5BOW Horizontal Bow *
5HSH Horizontal shife 40 *
5EWW EW width *
5EWP EW parabola *
5UCR EW upper corner parabola
5LCR EW lower corner parabola
5EWT EW trapezium
5VSL Vertical slope 42
5VAM Vertical amplitude 55
5SCL S-Correction 21
5VSH Vertical Shift 28
5VOF OSD Vertical Offset 40
HOF OSD Horizontall Offset 40
VX Vertical Zoom
6PAR Horizontal parabola
6BOW Horizontal Bow
6HSH Horizontal shife
6EWW EW width
6EWP EW parabola
6UCR EW upper corner parabola
6LCR EW lower corner parabola
6EWT EW trapezium
6VSL Vertical slope
6VAM Vertical amplitude
6SCL S-Correction
6VSH Vertical Shift
6VOF OSD Vertical Offset
HOF OSD Horizontall Offset
VX Vertical Zoom
RED Black level offset R 32 *
GRN Black level offset G 32 *

15
Maintenance Service and Trouble shooting


Specifications Variable
Item Default Value
Mark
WPR White point R 31 *
WPG White point G 26 *
WPB White point B 31 *
YDFP Y-Delay for PAL 7 *
YDFN Y-Delay for NTSC *
YDAV Y-Delay for AV *
TOP AGC Take-Over point 32 *
VOL Volume 44
9874 Output Gain of TDA9874A 26
AVLT TDA9874A AVL decay time 1
9860 Sub volume of TDA9860/59 69
IFFS Vision IF 2
HDOL Cathode drive level 5
AGC IF AGC speed 1
VF2B VG2 Brightness 50
0CON Listen:Contrast 0
0BRI Listen:Brightness 0
0COL Listen:Color 50
0SHP Listen:Sharpness 50
1CON Soft: Contrast 45
1BRI Soft: Brightness 45
1COL Soft: Color 50
1SHP Soft: Sharpness 50
2CON Standard: Contrast 70
2BRI Standard: Brightness 50
2COL Standard: Color 60
2SHP Standard: Sharpness 50
3CON Dynamic: Contrast 80
3BRI Dynamic: Brightness 50
3COL Dynamic: Color 70
3SHP Dynamic: Sharpness 50
OP1 Option 1 177
OP2 Option2 127
OP3 Option3 255
OP4 Option4 75
OP5 Option5 183
OP6 Option6 89
OP7 Option7 1



You can change the DATA with "*" mark when necessary.




16
Maintenance Service and Trouble shooting




No light and sound



Check to see if
Fuse3 is normal
Abnormal
Normal



Check VD503-VD, Check to see 110V 180V
506,C511, N501, etc. etc. voltage is normal
Normal
Abnormal
Check to see if the T to see all terminal
est
collector voltage of Resistance of load
VD512is 24V Is normal


Normal Abnormal Normal Abnormal

Check to see Check the control Check switch Check to see if
if , 8v, voltage of VD512 power unit rectifying tube
5v is normal or CPU power is normal


Normal Abnormal Normal Abnormal

Check The failure of Change Check the
N507,N508 horizontal unit or rectifying tube Loader
N201




17
Circuit Diagram


11. Circuit Diagram
1 2 3 4 5 6 7 8 9 10 11 12




C406 C703
S3
X 06 C331 IN O RD
MA B A G701 1P
T
R420 100K 1uF/ 16V 1R 2L R331 4. 7k 20V
103




+
SC

OKT
S C E - 21 L? R329 4. 7k C330 10/16V
V401 0. 01 R324 T
G702 1P




+
C1815 C307
I E
VDOin L
Ain Text Ain
R C405 4. 7k 0. 01u FO
10uF/ 16V
C407 C326 0. 01 N3 0 1 LA4 28 5 /8 7 (R) N3 0 2 LA4 2 85 /8 7 (L)
1uF/ 16V
C306
1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10




+
R421 C328 2 /1000u
5V R703 HV
VD O out
I E Rn
i Gn
i i
Bn A out