BBK LD1506SI-2 User manual

service manual
LD2006SI-2
LD1906SI LT1900S
LD1506SI-2 LD1506SI-3 LT1500S-2
LT1500S-3 LT2000S

LD2006SI-2 is a LCD TV with multiple functions. It adopts MST718 as main chip (MST718 has built-
in MCU and video processor). Video main board of this machine adopts 21903-X series PCB (only small
changes are made in PCB board numbers and service manual of LD2006SI-2 adopts the video main
board of 21903-5). This PCB integrates the circuit of DVD function and DVB function on video main
board. This PCB is widely used and there are many derived machines. Now we will introduce functions
and machine structure of several derived machines one by one. We list the following for readers to used
in order to know differences between each model.
List of Differences in Different Models
Explanation to LD2006SI-2 derived machines
Model
Video
main
board
TV
button
board
Remote
control
receiving
board
USB
board
Headph
one
board
DVD
button
board
Power
board Inverter
Conne
cting
board
Display
screen Remark
LD1506SI
-2 21903-5 41903-0 B1506-0 D1903-1 H1903-1 J1903-0 Adapter AK083-3
INV203-
2
SVA150XG
04TB 15"
TFT
Based on LD2006SI-2,
change display screen
to 15" screen, change
power board to adapter
and make the relevant
changes in video main
board
LD1506SI
-3 21903-5 41903-0 B1506-0 D1903-1 H1903-1 J1903-0 Adapter AK083-3
INV203-
2
BOEHT150
X02-100
15" TFT
Based on LD1506SI-2,
change MST718BE to
MST718BU PQFP,
change the
manufacturer of display
screen
LT1500S-
221903-5 41903-0 B1506-0 H1903-1 Adapter AK083-3
INV203-
2
SVA150XG
04TB 15"
TFT
Based on LD1506SI-2,
cancel DVD and card
read function
LT1500S-
321903-5 41903-0 B1506-0 H1903-1 Adapter AK083-3
INV203-
2
BOEHT150
X02-100
15" TFT
Based on LD1506SI-3,
cancel DVD and card
read function
LD1906SI 21903-6 41903-0 B1903-1 D1903-1 H1903-1 J1903-0 Adapter
AK083-3 INV403
M190A1-
L02 19"
TFT
Based on LD1506SI-2,
change display screen
and the matching circuit
LT1900S 21903-6 41903-0 B1903-1 H1903-1 Adapter
AK083-3 INV403
M190A1-
L02 19"
TFT
Based on LD1906SI,
cancel DVD and card
read function
LT2000S 21903-5 41903-0 B1903-1 H1903-1 @52006
-2UL INV607 G2006 SI-0
LC201V02-
SDB1 20"
TFT
Based on LD2006SI
2, cancel DVD and card
read function
LD2006SI
-2 21903-5 41903-0 B1903-1 D1903-1 H1903-1 J1903-0 @52006 -2UL INV607 G2006 SI-0
LC201V02-
SDB1 20"
TFT
Adopt MST718BE+20"
TFT screen

1. Introduction to LT2000S model
Based on LD2006SI-2, LT2000S cancels DVD/card read function, but other circuit and components
are totally the same with those of LD2006SI-2. Compared with LD2006SI-2 on the aspect of composition
of the player, LT2000S has no PCB components of USB board /DVD button board/video main board
(DVD function circuit is absent). As for working principle, we will not give any introduction, so please
refer to “LD2006SI-2 Service Manual”.
2. Introduction to LD1506SI-2 model
LD1506SI-2 is a 15” LCD TV, which changes display screen to 15” LCD TFT screen on the basis of
LD2006SI-2. According to parameters requirements, drive means and inverter components are
changed. Differences on video main board: 1) LD1506SI-2 adopts LVDS output means, while LD2006SI-
2 adopts TTL output means, so the peripheral circuit of LCD drive output part on MST718 has slight
difference; 2) 15” screen adopts 5V power supply, so IC702 is added to act as voltage stabilizing IC; 20”
screen adopts 12V power supply, so there is no need to add voltage stabilizing IC; 3) LD1506SI-2 adds
VGA input circuit according to design requirements to make the machine use as display; 4) LD1506SI-2
adopts adapter (AK083-3) to supply power, while LD2006SI adopts internal power board to supply
power, so power input end is added on video main board. Remark: as for inverter components and
power adapter working principle of this machine, you may refer to “LD1506SI Service Manual”; as for
video main board and other subsidiary board working principle, please refer to “LD2006SI-2 Service
Manual”.
3. Introduction to LD1506SI-3 model
LD1506SI-3 changes display screen and MST718 ob the basis of LD1506SI-2. The main
differences are: display screen is changed to BOEHT150X02-100 15” TFT screen; main IC MST718BE
is changed to MST718BU PQFP; other parts are totally the same. Please refer to “LD2006SI-2 Service
Manual” and “LD1506SI Service Manual” for details of working principle.
4. Introduction to LT1500S-2 model
LT1500S-2 cancels DVD function on the basis of LD1506SI-2 but other parts are totally the same.
Please refer to “LD2006SI-2 Service Manual” and “LD1506SI Service Manual”.
5. Introduction to LT1500S-3 model
LT1500S-3 changes display screen and MST718 on the basis of LT1500S-2. The main differences
are: display screen is changed to BOEHT150X02-100 15” TFT screen; main IC MST718BE is changed to
MST718BU PQFP; other parts are totally the same. Please refer to “LD2006SI-2 Service Manual” and
“LD1506SI Service Manual” for details of working principle.

6. Introduction to LD1906SI
LD1906SI changes display screen to 19” TFT screen on the basis of LD1506SI-2. Because of this,
boost components has alteration, that is, boost components are changed to INV403 (working principle is
the same with INV607 and you may refer to “LT2002S Service Manual). Display screen drive adopts
LVDS input method and other circuits' working principle is totally the same with that of LD2006SI-2.
During the course of servicing, please refer to “LD2006SI-2 Service Manual”.
7. Introduction to LT1900S model
LT1900S cancels DVD function on the basis of LD1906SI and other parts are totally the same with
those of LD1906SI. Please refer to “LD2006SI-2 Service Manual” for details of working principle.

Catalog
Chapter One About Maintenance
1.1 Safety precautions
1.1.1 Power supply
1.1.2 Precautions for antistatic
1.1.3 Precautions for display screen
1.1.4 Precautions for laser head
1.1.5 About placement position
1.2 Maintenance method
1.2.1 Electric resistance method
1.2.2 Voltage method
1.2.3 Current method
1.2.4 Element substitution method
1.2.5 Cutting method
1.2.6 Visualized method
1.2.7 Comparison method
1.3 Required device for maintenance
Chapter Two Functions and Operation Instructions
2.1.2 Set list
2.1.3 CONTROLS AND FUNCTIONS
Section Two DVD SEGMENT
2.2.1 Controls and functions
2.2.2 FUNCTION SETTINGS
Section One TV SEGMENT
2.1.1 Features
2.1.4 CONNECTION AND STARTING
2.1.5 TV MODE
2.2.3 OTHERS
1
1
1
1
1
2
2
2
2
2
2
2
2
3
3
3
4
4
4
5
5
7
7
9
9
9
12

Chapter Three Principle and Servicing
The previous manual: TV part
Section One Principle of the player
3.1.1 Function
3.1.2 Block diagram of the player
3.1.3 Function introduction to IC of the player
Section Two Unit Circuit Principle
Section Three Servicing Cases
3.3.2 Troubleshooting flow chart
Section Four
Section Three Servicing and Principle
The next manual: DVD part
Section One Principle of the player
3.1.1 Introduction to the player
3.1.2 Introduction to IC used by the player
Section Two Unit Circuit Principle
3.2.1 Introduction to laser head
3.2.2 Servo circuit
3.2.3 Laser power control circuit
3.2.4 CD/DVD conversion circuit
3.2.1 System control circuit
3.2.2 Audio circuit
3.2.3 Video circuit
3.2.4 Input circuit
3.2.5 Power circuit
3.3.1 Servicing cases
Waveform diagram
Section Five Function Introduction to IC
3.5.1 function introduction to SDRAM
3.5.2 function introduction to STV8216
3.5.3 function introduction to MST718
3.5.4 function introduction to Cd4052
3.5.5 function introduction to TDA7266D
3.5.6 function introduction to FSAV433
3.5.7 function introduction to HEF4094B
15
15
15
15
15
17
18
18
22
26
27
29
34
34
42
54
63
63
64
67
73
75
75
76
78
78
78
78
79
79
80
82
93

3.2.5 Disc slot-in circuit
3.2.6 Disc in/out circuit
Waveform diagram
Section Five Function Introduction to IC
3.5.1 function introduction to MT1389HD
3.5.2 function introduction to FLASH
3.5.3 function introduction to D5954
3.5.4 function introduction to 4558/4580
3.5.5 function introduction to 24CC02A
Chapter Cinque PCB board & Circuit diagram
Section One PCB board
Section Two Circuit diagram
Chapter six BOM List
3.2.7 Main axis control circuit
3.2.8 Decode circuit
3.2.9 Reset circuit
3.2.10 Video circuit
3.2.11 Audio circuit
3.2.12 USB/CARD circuit
Section Three Servicing Cases
3.3.1 Servicing cases
3.3.2 Troubleshooting flow chart
Section Four
Chapter Four Disassembly and Assembly Process
84
85
87
88
89
90
91
91
93
93
95
101
106
106
122
122
123
124
125
128
128
134
152

Chapter One About Maintenance
1.1 Safety precautions
1.1.1 Power supply
When maintenance personnel are repairing DVD TV, he should pay special attention to the power
with 220V 800V AC and 330V DC which will cause hurt and damage to persons!
1.1.2 Precautions for antistatic
Movement and friction will both bring static electricity which causes serious damages to integrated
IC. Though static charge is little, when a limited quantity of electric charge is added to large
scaleintegrated IC, as the capacitance is very small in the meantime, now the integrated IC is very much
easy to be struck through by static electricity or the performance will decrease. Thus static electricity
prevention is of extraordinary importance. The following are several measures to prevent static
electricity:
1. Use a piece of electric conduction metal with the length of about 2 metres to insert into the earth,
and Fetch the lead wire from the top of the surplus metal and connect to the required static electricity
device. The length and depth of the metal embedded under the earth should be determined according to
the wettability of the local soil. For humid places, it may be shorter, and longer and deeper for dry places.
If possible, it can be distributed and layed in terms of “#” shape.
2. On operating table-board, the antistatic table cushion should be covered and grounded.
3. All devices and equipments should be placed on the antistatic table cushion and grounded.
4. Maintenance personnel should wear antistatic wrist ring which should be grounded.
5. Places around the operating position should also be covered with electric conduction cushion or
Painted with antistatic paint.
1.1.3 Precautions for display screen
1. Display screen is breakable article, so please protect carefully when carrying and prevent fingers
or hard objects striking the screen to damage structure of the screen.
2. When cleaning screen, do not use organic chemicals. You should use cloth and use small
amount of special cleaning liquid in places difficult to clean.
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- 2 -
1.1.4 Precautions for laser head
1. Do not stare at laser head directly, for laser emission will occur when laser head is working,
which will Hurt your eyes!
2. Do not use wiping water or alcohol to clean laser head, and you may use cotton swab.
1.1.5 About placement position
1. Never place TV in positions with high temperature and humidity.
2. Avoid placing near high magnetic fields, such as loudspeaker or magnet.
3. Positions for placement should be stable and secure.
1.2 Maintenance method
1.2.1 Electric resistance method
Set the multimeter in resistance position and test whether the numerical value of resistance of each
point in the circuit has difference from the normal value to judge the trouble spot. But in the circuit the
tested numerical value of resistance is not accurate, and the tested numerical value of integrated IC's
pins can only be used for reference, so the elements should be broken down for test.
1.2.2 Voltage method
Voltage method is relatively convenient, quick and accurate. Set the multimeter in voltage position
and test power supply voltage of the player and voltage of a certain point to judge the trouble spot
according to the tested voltage variation.
1.2.3 Current method
Set the multimeter in current position and test current of the player of a certain point to judge the
trouble spot. But when testing in current method, the multimeter should be series connected in the
circuit, which makes this method too trivial and troublesome, so it is less frequently used in reality.
1.2.4 Element substitution method
When some elements cannot be judged good or bad, substitution method may de adopted directly.
1.2.5 Cutting method
Cutting method should be combined with electric resistance method and voltage method to use.
This method is mainly used in phenomena of short circuit and current leakage of the circuit. When
cutting the input terminal voltage of a certain level, if voltage of the player rises again, it means that the
trouble lies in this level.

1.2.6 Visualized method
Directly view whether abnormalities of collision, lack of element, joint welding, shedding welding,
rosin joint, copper foil turning up, lead wire disconnection and elements burning up among pins of
Elements appear. Check power supply of the machine and then use hands to touch the casing of part of
elements and check whether they are hot to judge the trouble spot. You should pay more attention when
using this method to check in high voltage parts.
1.2.7 Comparison method
A same good PC board is usually used to test the correct voltage and waveform. Compared these
data with those tested through fault PC board, the cause of troubles may be found.
Through the above maintenance method, theoretical knowledge and maintenance experience, all
difficulties and troubles will be readily solved.
1.3 Required device for maintenance
Audio Generator
Digital oscillograph ( 100MHE)
SMD rework station
Multimeter
Soldering iron
Pointed-month pincers
Cutting nippers
Forceps
Electric screw driver
Terminals connecting cord
Headphone
Microphone
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