Haier 29FV6 User manual

Features
zSoft change & Curtain screen technology
zProgram scanning, calendar, digital bass and child
lock
zDigital noise reduction and picture still
zProgram scan & program swap
zDigital comb filter & Mighty speed control
29FV6
COLOUR TELEVISION
Service Manual
Haier Grou
p

2
Contents
1. Product code illumination and series introduction ………….….…..3
2．Features………………………………………………….…………...…..3
3．Specifications………………………………………………..…………...4
4．Safety Precaution……………………………………………………….….5
5．Warning and cautions………………………………………………….….6
6．Net Dimension …………………………………………………………….12
7．Parts and Functions………………………………………………………12
8．Remote controller Functions……………………….…………………..13
9. Maintenance Service and Trouble Shooting…………………..……14
10. Circuit Diagram………………………………………………..………....15
11. Circuit Explanation…………………………………………..………….17
12. Signal channel……………………………………………………..……24
13. Exploded View…………………………………………………….……..25
14. List of Parts…………………………………………………….…………26
15. Damageable Parts List…………………………………………….……55
16. Information of Resistors and Capacitors…………………….……..56
Contents

3
1. Product code illumination and series introduction
29 F V6-A
CRT catercorner 29 inch (68cm)
Product code illumination and series introduction & Features
2．Features
zSoft change & Curtain screen technology
z16：9 mode, calendar, digital bass and child lock
zDigital noise reduction and picture still
zProgram scan & program swap
zDigital comb filter & Mighty speed control
zTwo AV input & One S terminal input & One AV output
zVGA display 800×600
z1080i 50Hz/60Hz INPUT
Pure flat CRT
Appearance serial

4
3. Specifications
NO. FUNCTION
39 NO. of built-in speakers 4
40 Audio output power(W) 25W
41 Total power input（W）180W
42 Voltage range（V）160-250V
43 Power frequency（Hz）50Hz
44 Time of sleep timer(MINS)
45 Net weight(KG)
46 Gross weight(KG)
47 Net dimension(MM)
48 Packaged dimension(MM)
49 Quantity for 20' container
50 Quantity for 40' container
51
PARAMETER
Quantiry for 40' high container
52 Acquired certificate
53
APPROVAL
Suitable market
Specifications
NO. FUNCTION
1 CRT（29") UOC
2 Color system PF
4 NO.of preset channels 225
5 OSD languages ENGLISH,RUSSIAN
6 Comb filter YES
SVM YES
Black stretch YES
Noise Reduce YES
CTI YES
Screen saver YES
7
P
I
C
Multi-picture modes YES
8 Audio system M,D/K,I,B/G
9 MTS YES
10 AV stereo YES
11 Super woofer YES
12 Surrounding sound YES
13 Treble/bass boost YES
14 Left/right balancer YES
15 Multi-audio modes News,Theatre,Music,Standard
,
16
A
U
D
I
O
Mute YES
18 AV output 1
19 AV input 2
21 Back AV input 1
22
DVD terminal
（interlace and
progressive）
YES
S-video jack YES
23
J
I
C
VGA input YES
24 Digital curtain Y
25 Slow fading on & off Y
26 Semitransparent menu Y
27 No-flashing channel
changing Y
28 ZOOM Y
29 16:9 mode
30 Games Y

5
4. Safety Precautions
INPORTANT SAFETY NOTICE
These parts are identified by many electrical and mechanical parts in this chassis have
special safety-related characteristics.
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.
Safety Precautions

6
5．Warning and Cautions
1. When you clean the TV set, please pull
out the power plug from AC outlet. Don't
clean the cabinet and the screen with
benzene, petrol and other chemicals.
4. To prevent the TV set from firing and
electric shock, don't
make the TV set rain
or moisture.
2. In order to prolong the using life of the
TV set, please place it on a ventilated
place.
5. Don't open the back cover, otherwise it is
possible to damage the components in the
TV set and harm you.
3. 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.
Warnin
g
and Cautions

7
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 and any of the safety precautions, always follow the safety precautions.
Remember : Safety First.
General Servicing Precautions
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.
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”.
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.
4. Do not spray chemicals on or near this receiver or any of its assemblies.
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.
6. Do not defeat any plug / socket B+ voltage interlocks with which receivers covered by
this service manual might be equipped.
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.
Warning and Cautions

8
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.
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.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid state) devices can be damaged easily by static electricity.
Such components are usually called Electrostatically Sensitive (ES) Devices. Examples of
typical ES 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.
1. 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.
2. 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.
3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.
4. 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.
5. Do not use freon-propelled chemicals. These can generate electrical charges
sufficient to damage ES devices.
6. 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).
7. 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.
8. 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
Warning and Cautions

9
1. 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.
2. Use an appropriate gauge of RMA resin-core solder composed of 60 parts tin/40 parts
lead.
3. Keep the soldering iron tip clean and well tinned.
4. 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.
5. 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.
c. Quickly 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.
6. 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.
Warning and Cautions

10
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
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
1. Clip each fuse or resistor lead at top of the circuit board hollow stake.
2. Securely crimp the leads of replacement component around notch at stake top.
3. 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
Warning and Cautions

11
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).
1.Carefully remove the damaged copper pattern with a sharp knife. (Remove only as much
copper as absolutely necessary).
2.Carefully scratch away the solder resist and acrylic coating (if used) from the end of the
remaining copper pattern.
3.Bend a small “U” in one end of a small gauge jumper wire and carefully crimp it around
the IC pin. Solder the IC connection.
4.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.
1. 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.
2. 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.
3.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.
Warnin
g
and Cautions

12
6．Net Dimension
L×W×H=840×630×680
7．Parts and Funcitions
Front and side panel of the TV set
(AUDIO-R)
Side AV term inal
VIDEO
R
(VIDEO)
(AUDIO-L)
TV/AV MENU
V-
V+
P-
P+
D 29FV6 , D 34FV6 M odel
M E N U
Volum e up/ dow n
Channel p o s ition up/dow n
TV/Video
(input selector）
In fra re d re c e iver
Power switc h
When using S terminal, please pull out video 1 input terminal
Net Dimension

13
8. Remote Controller Functions
1
2
3
4
5
6
7
8
9
11
12
13
14
15
16
17
18
19
20
21
23
22
24
10
25
26
27
28
123
456
789
0
ZOOM
-/--
CAL./EXIT
MUTE TV/AV
POWER
HDM SCAN
CALL/HELP
P. S TD S.STD
CH+
CH-
VOL- VOL+MENU
PICTURE
FUNCTION TUNE
SHUTTLEFAVOR ITE
SOUND
STILL
SWAP
T.SKIP
TIME H.LOCK D.ALBUM
1
3
5
7
2
6
8
4
9
10
12
11
13
15
14
16
18
17
19 20
21
23
25
22
24
26
27 28
Function buttons of the remote control
Remote Controller Functions
Figure 3

14
9. Maintenance Service and Trouble Shooting
1)Sub-brightness adjustment
Set the picture mode to standard, select the eight-level grey scale signal, choose the white
balance / sub-brightness modulating function from the menu of factory mode and set to the “SB”, use
the key-presses “volume+” and “volume-”to modulate it. In order to distinguish the 8-graded grey signal
just as well, the sub-brightness is usually around 7. And we set it to 10 in order to make the brightness
cross the screen easier through comment.
2)white balance adjustment
White balance is preset in factory. Usually, the light balance digits (RDRV, GDRV, BDRV) are at 31
more or less. And the darken balance digits (RDRV, GDRV, BDRV) are at about 7. After a comment , we
set the bright balance parameter to “40,35,50” for arising the screen’s bright-across.
3)enter/exit the factory mode
①Directly press the button “factory” on the factory remote controller. Press the menu button to choose
suitable menu, then use the buttons “program+” and “program-” to choose the item which you want to
tune, then use the “volume+” and “volume-” to tune it.
②press the “V-” of local control to the min, then press the“v+” and “v-” at the same time to enter the
factory mode.
③when receiving the signals normally, (the factory mode is on)we can turn off the TV alternately to exit
from the factory mode. After exiting from the factory mode, user would not be able to use the factory
menu to do the related modulation.
4)geometry distortion adjust
In factory mode, enter the geometry distortion adjust menu, in each of these states——PAL、NTSC、
HDTV50Hz、HDTV60Hz、YPbPr、VGA，we can do modulations according to four kinds of scanning
modes (including 100Hz、1250line、60P、75I). these modulations include VSC , VLIN, VP50,
HIT, HPS, WID, DPC , KEY, PARA, BOW, UCNR, LCNR, and so on.
5)AGC adjust
make sure that the input RF signal is about 60dB, then adjust the UR101 to make the noise of the
image as little as possible.
Maintenance Service and Trouble Shooting

10. Circuit Diagram
a. Pane hint picture
Circuit Diagram
Tuner Surface Filter
Digital Batch Circuit & CPU
Switch
Subsidiary Power Supply
Remote Control
TV SIGNAL
AV YCbCr
YPbPr VGA
AV OUT AUDIO OUT
(L/R/BASS)
SCL&
SDL
TDA 7497
AV TERMINAL
LV1116
8V&5V
FBT
28V
V-IC
H-IC
8V 5V
15V
28V
DARK CURENT
CHECK
RGB
SIGNAL TDA6111
SYNC
±15V
200V
FOCUS
SCREEN
130V
H-DY
V-DY

16
Circuit Diagram
Circuit Diagram

17
11. Circuit Explanation
A. Electric circuits
1. Power
The FAIRCHILD power supply layout is applied and the switch transformer has four circuit
outputs: +B (130V), +15V, +32V and +7.5V
+B output:
Voltage produced by the transformer pin 10 shall after being rectified have four
circuits. Circuit 1 provides +B voltage through R810 to line output transformer.
Circuit 2 provides feedback voltage to controllable silicon through R815 and R815A.
Circuit 3 provides voltage to VM board. Circuit 4 provides tuning voltage to tuner
through R811.
+15V output
Voltage produced by the switch transformer pin 14 and rectified shall have the
following circuits. Circuit 1 provides audio amplification voltage to TDA6111Q.
Circuit 2 provides +12V current to optical coupler. Circuit 3 provides +15V voltage
to N804(KA7630). Circuit 4 provides +12V voltage through V804. Circuit 5 provides
input voltage to line driving transformer. Circuit 6 provides voltage to VM.
+32V output
Switch transformer pin 16 provides rectified voltage to accompany sound amplifier
N602（TDA7497）through VD807.
+8V output
+8V Voltage produced by N804 (KA7630) has 4 circuits. Circuit 1 provides power to
decoder board. Circuit 2 provides power to N701 (LV1116) through L701.
Three sources of +5V output
First source is (+5V) provided by pin 9 of N804 to CPU and decoder board. Second
source is (+5V) provided by N101 (KA78R05) to N102 (LA75503) and tuner AGC.
Third source is (+7.5V) from pin 18 of the switch transformer, and the voltage is
inverted to (+5V2) through V801 (2SC3852A) and then provided to the decoder
board.
Forward and flyback voltage +16V/+16V is provided to N301 (TDA8177) by pin 6 and
7 of FBT after being rectified; pin 3 provides 205V to audio frequency amplification
after being rectified.
2. Signal channels
TV signals are received, mixed, amplified and produced as 38M intermediate frequency
signals by the tuner. The 38M intermediate frequency signals shall be enter quasi
Circuit Explanation

18
separation sound surface filter Z101 (pictures) and Z102 (sound) through two circuits after
advance amplification. The sound and picture signals through filter shall be transmitted
through pin 19/20 and 16 of N102. The audio frequency signal will be filtered and
demodulated inside N102 (LA75503). The demodulated sound signal from pin 24 will be
transmitted to pin 5/12 of N702 and, after compared and selected with AV1 sound signal
sent from pin 3/13, to pin 2/35 of N701 through pin 4/14, and finally, the left and right
channel sound inputs will be amplified by N701. Pin 14/23 will be the left and right stereo
channels for high and low sound as well as surround sound treatment. Bass sound signals
from pin 15 will be transmitted to N602 and, after being amplified, to the left and right
speakers and bass speaker through pin 12/14 and pin 3. Pin 5/32 of N701 produces
sound frequency to AV. Component sound signals of AV, HDTV, VGA and DVD are
transmitted through pin 2/35 and 4/33 of N701 and treated for high, low and surround
sound and amplified.
Audio signal is transmitted to decoder board STV75503 through pin 4 and, after
being selected by AV1 and terminal S through N702 (TC4053), to VIDEO1/Y-IN.
VIDEO1-C-IN will transmit chrominance signal to terminal S, which is given priority to pin
AV1. VIDEO2-IN transmits AV2 signal. DVD interleaves component is transmitted to Cr,、
Cb and、 Y. TV/AV1/AV2/DVD signals can be selected and treated through STV6688 to send
to STV2310 to do general digital treatments, and audio transmitted to AV output terminal
through decoder board VIDEO-OUT. Video signals of TV/AV1/AV2/DVD can be
transformed through STV2310 for 8-bit A/D and transmitted to SATV3500 which will
process the digital signals for frequency multiplication (line frequency), and then for
motion compensation. After these two treatments, the signals will be deal with for D/A
inversion and finally become Y, U and V signals. Line by line component YPbPr of Y, U, V
and HDTV, DVD from ST3500 is transmitted, after selected by Ta1370 and amplified by
TDA9332H, toTDA6111Q together with R/G/B signals from VGA and OSD R, G, B signals
from CPU. VGA synchronic line and field signals, H-VGA and V-VGA, and TV synchronic
line and field signals, HTV and VTV, will be transmitted to TDA9332H after being selected
inside TA1370 that the Y signal of HDTV signal and DVD signal’s line by line component
for formation of line and field drivers。In addition, H-VGA is transmitted to CPU for VGA
test and identification. The alphabetic R/G/B signals produced by M29KW016 and
the alphabetic blanking signals will be amplified by the audion and then transmitted to
OSD-R, OSD-B, OSD-G, OSD-BLANK of decoder board N3 (TDA9332H). N3 (TDA9332H)
will transmit the alphabetic signals, after being amplified, to TDA6111Q.
Because of the FLASH chip we used in the digital circuit, in order to improve the
problem program ,we can plug the J_DCU pin into the digital board and write a new
program down through the burn-in machine.
3. vertical output
The output circuit of this TV set uses TDA8177 vertical scanning integration module, pin 5
for vertical scanning output and connected with the vertical-deflecting coil. Both positive
and negative saw tooth waves transmitted by TDA9332H of digital board will be entered
by pin and , repaired and amplified by TDA8177 and transmitted by pin . TDA8177①⑦ ⑤

19
is operational with dual power supply, forward and backfly power supply, obtained through
line output amplification and of +14V and -14V, respectively.
4. Muting circuit and shut-down silence circuit
The muting circuit enables N901(CPU) to generate high level to raise the power level of
pin 10 of N602 (for left and right audio channels control) and pin 9 (for bass sound control)
to achieve the muting result (output at high level of pin 10 and 9 of N602 is 0V). When
channels are changed, CPU sends high level (high level takes a bit longer time than
channel option.) to realize the mute effect of N602 while changing channel and then
eliminate the noise when changing channels.
Shut-down silence circuit works by changing +15V to 0 while the TV set is turned off, and
C641 discharges to enable V602 through and, as a result, to raise the voltage of pin 10
and 9 of N602 for a mute result.
5.Geomagnetism calibration circuit
Working principles: Geomagnetism calibration is to utilizing the stable magnetic field
generated by direct current volts of geomagnetism calibration coils to solve the problem of
picture incline resulted from different geomagnetism in different places. In most cases, it is
to use two constant voltages for the calibration. This circuit is to use +15V direct voltage
provided by line package and PWM wave generated by CPU for geomagnetism
calibration.
Details of the circuit: Audion V950 and V951 function as switch on and off. When V950
base electrode is of high level, V950 on, V951 off, C903 discharge through R901 and
V950. C902 recharge through R902 and R904. When V950 base electrode is of low level,
V950 off, V951 on, and C903 recharge through R903 and R901. C902 discharges through
R904 and V951. Correcting PWM wave duty ratio may diversify switch-on and off time of
V950 and V951, and discharging or recharging time of C902 and C903, and voltage
accumulated in C902 and C903, resulting in different output voltage.
Following are the data of some circumstances:
When geomagnetism calibration status is –50, PWM duty ratio is about 1 (almost high
level), V950 B/C/E voltages are 0.77V, 0.1V and 0.01V (through), respectively, V951
B/C/E voltages are 0.06V, 12.21V, 13.35V and 11.94V, respectively. Voltages at two ends
of the calibration coil are 11.94V and -0.01V, respectively.
When geomagnetism calibration status is 50, PWM duty ratio is about 0 (almost low level),
V950 B/C/E voltages are 0.12V, 14.46V and 0.01V (Off), respectively, and V951 B/C/E
voltages are 0.72V, 0.15V and 0.01V (through), and V952 B/C/E voltages are 0.15V,
14.082V and -0.06V, respectively. Voltages at two ends of the calibration coil are -0.06V
and 14.029V, respectively.
All and all, when geomagnetism calibration data changes from –50 to +50, voltages at the
two ends of the calibration coil will also change from 11.94V to -0.06V and from 0V to
Circuit
Explanation

20
14.29V, resulting in a stable magnetic field to adjust picture incline caused by
geomagnetism.
6. VM circuit
Basic principle: VM tone circuit uses VM tone coil to produce a magnetic field. When the
circuit turns bright or dark, scan speed will also change. When brightness signals appear,
scan speed will slow down to make the brightness signals stronger. When darkness
signals appear, scan speed will become quicker to make darkness signal weaker. The
picture signals change area profile will become prominent to achieve better display result.
B. Functions of main circuits
1. Power IC KA5Q1265RF
KA5Q1265RF is developed by Samsung for integrated circuit for switch power supply,
incorporating PWM controller, standby low energy consumption and MOSFET. Interior
installation include current PWM controller, 650V MOSFET under voltage lock for current
testing. Heat protection and automatic reset circuit for defective status to perfect circuit
protection.
Functions of pins: Pin : initial input level; Pin①②：grounding; Pin ③：power supply 24V,
positive power input; VCC 11~12V in standby mode; Pin : optical coupler, wrong signals④
of output voltage feedback and provided as input; control circuit will be locked if voltage
reaches 7.5V; Pin : switch oscillation for outside⑤synchronized input. Control circuit will
be locked if voltage reaches 12V.
2. KA7630 (multi circuit regulated output circuit)
This circuit is designed to ensure the TV set is powered by 5V and 8V.
Pin and pin : voltage input (12V); Pin : reset for①② ③ optical coupler; Pin : output④
switch control, disconnecting 8V output; Pin : grounding; Pin : CPU reset; Pin and⑤⑥ ⑦
pin : idle; Pin : 8V output; Pin : 5V output⑩⑧ ⑨
3. LV1116 (3 band dual sound channel digital control audio frequency processing circuit)
This circuit functions for correcting volume, treble, bass and balance, option of 3 circuit R
and L audio frequency and output of 2 circuit audio frequency (including one circuit for AV
output).
Functions of pins
Pin (2)/(35), (3)/(34), (4)/(33): left/right sound channel input; pin (5)/(32): AV left/right
stereo sound output; pin (20): clock wire; pin (19): data wire; pin (1): grounding; pin (17):
power 8V; pin (14)/(23): left/right audio frequency output; pins （9）/（28）,（10）/（27）,
（11）/（26）: treble and bass effect processing; pin (25): bass sound frequency output; pin
(22): bass sound wave filtering; pin (16): power wave filtering
Circuit Explanation