Changhong LS0B Schematic
LCD/PDP TV
MODEL: LS0B CHASSIS
SERVICE MANUAL
(18.5 inches LED TV as an example，General version)
Please read this manual carefully before service.
CATALOG
Chapter1:Safety and notes..........................................................................................3
1.1 Installation notes .................................................................................................................3
1.2 Attention points of operation and using ..............................................................................3
1.3 Storage notes.......................................................................................................................3
1.4 Dismantling notes ...............................................................................................................3
1.5 High-voltage warning .........................................................................................................3
Chapter2: Whole machine standard and terminal functions..................................4
2.1 Basic standard .....................................................................................................................4
2.2 Introduction of terminals(practicality photos).....................................................................5
Chapter3:Main chip functions and brief introductions of power supply...............6
3.1 MAIN IC and functions of LS0B........................................................................................6
3.2 Pin function description of LS0B chip................................................................................6
3.3 Brief introduction of power supply...................................................................................10
Chapter4: The chassis frame diagram, mainboard power supply systems,
mainboard interface definition and the waveform of key points .......................... 11
4.1 The chassis frame diagram................................................................................................ 11
4.2 Power supply system.........................................................................................................11
4.3 The waveform of key points .............................................................................................13
Chapter5: Software upgrade tooling,software upgrade instructions,software
initialization,parameter setting,software version and screen matching
instructions................................................................................................................. 14
5.1 Software upgrade tooling ..................................................................................................14
5.2 Software upgrade instructions...........................................................................................14
5.3 Software initialization .......................................................................................................18
5.4 Software version ...............................................................................................................19
Chapter6:Classical accident maintenance procedures and examples...................20
6.1 Clues of can’t boot ............................................................................................................20
6.2 Common problems for your reference:.............................................................................22
Chapter7: Spare Part Lists.......................................................................................23
Chapter8: Factory mode parameter setting instructions and notes.........................24
8.1 Enter into the factory mode...............................................................................................24
8.2 Setting method of factory menu........................................................................................26
Chapter9:Instructions of simple factory debugging specification.........................27
9.1 Clear EEPROM ,and set the parameters after upgrading according to the upgrade
instructions..............................................................................................................................27
9.2 Check each channel/source to see if the image and sound are normal..............................27
2
Chapter 1: Safety and notes
1.1 Installation notes
(1) Please don't beat or rub, scratch the surface of the LCD screen heavily, don’t touch it with
hand casually.
(2) When the screen is dirty, please clean it with absorbent cotton or cotton cloths lightly.
(3) Please clean the screen timely when water or other viscosity pollution falls on it, which may
make the LCD face or color changes.
(4) Please don’t make the LCD screen shocked by a strong external force.
1.2 Points of operation and using for attention
(1) Please unplug the power cable before moving LCD screen.
(2) Please don’t change the mainboard’s original setting; otherwise brightness, white balance etc.
may not meet the specification.
(3)The amount of radiation of long time use at room temperature is larger than that at low
temperature.
(4) Please note that the long displaying image may remain at the top when shutdown the
machine.
(5) Please avoid the impact from mobile phone to protect your TV.
1.3 Storage notes
(1)When store for a long time, please keep the temperature between 0℃to 40℃, don’t expose the
TV to the sun , the humidity should be less than 85％RH.
(2)Please don’t put your TV under high humidity and high temperature circumstance, e.g.
temperature: 60℃, humidity:85%RH.
(3)Please don’t put your TV under low temperature circumstance, e.g. temperature lower than
25℃.
1.4 Dismantling notes
(1) As LCD screen can be damaged easily when dismantle, please pay attention to protect it.
(2)Please pay attention to the position of each screw when dismantle in case of beating the wrong
position when install which may lead to crack or slide of the face frame.
(3) If you need to dismantle the power board or the main board, please attention the position and
direction of each line, especially the direction of the screen line, in case of causing accident
when install. Before dismantle, we can take some photos of the line routes for the comparison
of installing.
(4)After check and maintenance, please assure that there is no foreign body in the machine when
install.
1.5 High-voltage warning
The high-voltage of the LCD screen is generated by the power supply step-up board, without
attention to exposure to high voltage; one may meet a serious electric shock.
3
Chapter2: Whole machine standard and terminal functions
2.1 Basic standard
item standard
visual area 18.5 inches（diagonal） (CPT)
aspect ratio 16:9
resolving ratio 1366 x768
visual area H x V 409.8m m (H) ×230.4m m (V)
display color 16.7 million
LCD Panel
contrast 1000:1
brightness 250cd/m2
visual angle 170°(horizontal)/ 160° (vertical)
response time 5ms
backlight life 25000 hours
the parameters are
for reference only,
the specification
should accord to
the standard of the
panel of the batch
orders
TV function
audio and video
signal input
Video output
Audio
Power
Panel rotation
sound system B/G、D/K、I、M
color system PAL / SECAM / NTSC
AV RCA x 1 Audio L/R x 1
COMPONENT YPbPr x 1
HDMI HDMI x1 support to1080P
plug and use USB2.0
PC input
input frequency
recommend 1024x768(60HZ)
Output CVBS signal
Audio output L / R
power supply AC100V~240V, 50/60Hz
power consumption <48W
Front/back/rotation - 10° / + 10° / ± 35°
support to1080P ，Audio L/R
x 1,
H: 31.5K -106KHz
V: 60Hz to 85Hz
V:（recommend 60HZ）
Output TV and AV
signal ,Audio L/R
5W two built-in speaker.
ear phone
USB
requirement for circumstance
appearance size
net weight
4
plug and use 2.0
operation temperature
storage temperature
operation humidity
W x H x D
no accessory
+ 0° ~ + 40° ，
- 25 ° ~ + 60°
10% ~ 85%
Pls. refer to the TV
specification
Pls. refer to the TV
specification
2.2 Introduction of terminals (practicality photos)
ATTENTION:
1. HDMI and YPbPr support to 1080P (max. resolution)。
2.The recommendation resolution of PC input is 1024X768。
3. AV output supports TV input /AV output，AV input /AV output。
5
p
Chapter3: Main chip functions and brief introductions of power
supply
3.1 Main IC and functions of LS0B
No. Item no. Model Main Function
Processor with Video Decoder,
1 U200 MST6M182VG-LF-Z1
2 A001 CDT-3BP4I1-34
3 U202 EN25Q32A-100HIP
4 U806 SY8008B
5
6 U804 LR1117/A-2.5$AZ1117H-2.5TR
6 U805 LR1117/A-1.8$AZ1117H-1.8TRE1
9 U701 SA7454 Audio Amplifier
10 Y200 JA18AS-24MHZ Crystal resonator
11 U001 AS7805ADTR-E1
U802、
U803
LR1117/A-3.3$AZ1117H-3.3TR
MCU,HDMI decoder,LVDS transmiter
etc.
Tuner, output dfferential IF signal
Flash memory, Place the main control
rogram
DC-DC，DC voltage converter
LDO（three terminal regulator）
LDO（three terminal regulator）
LDO（three terminal regulator）
LDO（three terminal regulator）
3.2 Pin function description of LS0B main chip
3.2.1: The main chip MST6M182VG-LF-Z1 instraction
6
3.2.2 :Pin function of CDT-3BP4I1-36 tuner：
No.
Terminal name Description
1 NC Not connected
2 AGC RF AGC output 0~4V
3 VCC Supply voltage 5V
4 GND Ground
5 VT Not connected
6 AS Address select
7 SCL Clock
8 SDA Data
9
10
11
12
IF1 IF output 1
IF2 IF output 2
TU 33V
NC Not connected
3.2.3:Pin function of EN25Q32A flash memory
No. Terminal name Description
1 CS# Chip Enable
7
2 DO（DQ1） Serial Data Output(Data Input output1)
3 WP#(DQ2) Write Protect(Data Input output2)
4 VSS Ground
5 DI（DQ0） Serial Data Input(Data Input output0)
6 CLK Serial Clock Input
7 NC（DQ3） No Connect(Data Input output3)
8 VCC Supply Voltage(2.7-3.6V)
3.2.4: Pin function of MP1482 (DC-DC converter)：
No.
Terminal name Description
1 BS High-Side Gate Drive Boost Input
2 IN Input
3 SW Output
4 GND Ground
5 FB Output voltage feedback
6 COMP Calibration compensation
7 EN Enable switch
8 SS Soft start control
3.2.5 :Pin function of 1117/A-3.3 and 1117/A-2.5 ：
3.2.6: Pin function of AO4803 (Dual-channel enhanced MOSFET) ：
No.
Terminal name Description
1 S2 Source 2
2 G2 Gate 2
3 S1 Source 1
4 G1 Gate 1
5,6 D1 Drain 1
7,8 D2 Drain 2
8
3.2.7： Pin function of SA7454/TDA1517P(audio amplifier)：
No.
Terminal name In/Out
1 /CS I Input selection
2 DO O Data Output
3 WP# I Write protection
4 VSS Ground
5 DI I/O Date Input/Output
6 CLK I Serial clock input
7 NC I Output remains
8 VCC Power
3.2.8：Pin function of AS7805 ：
Description
9
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