Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in the
Schematic Diagram and Exploded View.
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent
Shock, Fire, or other Hazards.
Do not modify the original design without permission of 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 resulting in personal injury
from electrical shocks.
It will also protect the receiver and it's components from being
damaged by accidental shorts of th e cir cuitry that may be
inadvertently introduced during the service operation.
If any fuse (or Fusible Resistor) in this TV receiver is blown,
replace it with the specified.
When replacing a high wattage resistor (Oxide Metal Film Resistor,
over 1 W), keep the resistor 10 mm away from PCB.
Keep wires away from high voltage or high temperature parts.
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
be sure the set is safe to operate without damage of electrical
shock.
Leakage Current Cold Check(Antenna Cold Check)
With the instrument AC plug removed from AC source, connect an
electrical jumper across the two AC plug prongs. Place the AC
switch in the on position, connect one lead of ohm-meter to the AC
plug prongs tied together and touch other ohm-meter lead in turn to
each exposed metallic parts such as antenna terminals, phone
jacks, etc.
If the exposed metallic part has a return path to the chassis, the
measured resistance should be between 1 MΩ and 5.2 MΩ.
When the exposed metal has no return path to the chassis the
reading must be infinite.
An other abnormality exists that must be corrected before the
receiver is returned to the customer.
Leakage Current Hot Check(See below Figure)
Plug the AC cord directly into the AC outlet.
Do not use a line Isolation Transformer during this check.
Connect 1.5 K / 10 watt resistor in parallel with a 0.15 uF capacitor
between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Measure the AC voltage across the resistor using AC voltmeter
with 1000 ohms/volt or more sensitivity.
Reverse plug the AC cord into the AC outlet and repeat AC voltage
measurements for each exp ose d metallic par t. Any voltage
measured must not exceed 0.75 volt RMS which is corresponds to
0.5 mA.
In case any measurement is out of the limits specified, there is
possibility of shock hazard and the set must be checked and
repaired before it is returned to the customer.
CAUTION: Before servicing receivers covered by this service
manual and its supplements and addenda, read and follow the
SAFETY PRECAUTIONS on page 3 of this publication.
NOTE: If unforeseen circumstances create conict between the
following servicing precautions and any of the safety precautions
on page 3 of this publication, 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 mod-
ule or any other receiver assembly.
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 part substitution or incorrect polarity
installation of electrolytic capacitors may result in an explosion hazard.
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. Do not spray chemicals on or near this receiver or any of its
assemblies.
4. Unless specied 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
non-abrasive applicator; 10 % (by volume) Acetone and 90 %
(by volume) isopropyl alcohol (90 % - 99 % strength)
CAUTION: This is a ammable mixture.
Unless specied otherwise in this service manual, lubrication of
contacts in not required.
5. Do not defeat any plug/socket B+ voltage interlocks with which
receivers covered by this service manual might be equipped.
6. 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.
7. 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.
8. Use with this receiver only the test xtures specied in this
service manual.
CAUTION: Do not connect the test xture 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 commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES
devices are integrated circuits and some eld-effect transistors
and semiconductor “chip” components. The following techniques
should be used to help reduce the incidence of component damage caused by static 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 reasons 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 solder removal device. Some solder
removal devices not classied as “anti-static” can generate
electrical charges sufcient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate
electrical charges sufcient 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 harmless motion such as the
brushing together of your clothes fabric or the lifting of your
foot from a carpeted oor can generate static electricity sufcient to damage an ES device.)
General Soldering Guidelines
1. Use a grounded-tip, low-wattage soldering iron and appropriate
tip size and shape that will maintain tip temperature within the
range or 500 °F to 600 °F.
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 wirebristle (0.5 inch, or 1.25 cm) brush with a metal handle.
Do not use freon-propelled spray-on cleaners.
5. Use the following unsoldering technique
a. Allow the soldering iron tip to reach normal temperature.
(500 °F to 600 °F)
b. Heat the component lead until the solder melts.
c. Quickly draw the melted solder with an anti-static, suction-
type solder removal device or with solder braid.
CAUTION: Work quickly to avoid overheating the circuit
board printed foil.
6. Use the following soldering technique.
a. Allow the soldering iron tip to reach a normal temperature
(500 °F to 600 °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 ows 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
Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent at against the circuit foil. When holes are the 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 in paragraphs 5 and 6 above.
Removal
1. 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.
2. Draw away the melted solder with an anti-static suction-type
solder removal device (or with solder braid) before removing
the IC.
Replacement
1. Carefully insert the replacement IC in the circuit board.
2. Carefully bend each IC lead against the circuit foil pad and
solder it.
3. Clean the soldered areas with a small wire-bristle brush.
(It is not necessary to reapply acrylic coating to the areas).
1. Remove the defective transistor by clipping its leads as close
as possible to the component body.
2. Bend into a "U" shape the end of each of three leads remaining
on the circuit board.
3. Bend into a "U" shape the replacement transistor leads.
4. 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
1. Heat and remove all solder from around the transistor leads.
2. Remove the heat sink mounting screw (if so equipped).
3. Carefully remove the transistor from the heat sink of the circuit
board.
4. Insert new transistor in the circuit board.
5. Solder each transistor lead, and clip off excess lead.
6. Replace heat sink.
Diode Removal/Replacement
1. Remove defective diode by clipping its leads as close as possible to diode body.
2. Bend the two remaining leads perpendicular y to the circuit
board.
3. Observing diode polarity, wrap each lead of the new diode
around the corresponding lead on the circuit board.
4. Securely crimp each connection and solder it.
5. 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.
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
Excessive heat applied to the copper foil of any printed circuit
board will weaken the adhesive that bonds the 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 ensure 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 the
it does not touch components or sharp edges.
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.
4Scart Jack (1EA)PAL, SECAMScart 1 Jack is Full scart and support RF-OUT(analog).
5Video Input RCA(1EA)PAL, SECAM, NTSC4 System : PAL, SECAM, NTSC, PAL60
6Component Input (1EA)
7RGB InputRGB-PC
8HDMI Input (3EA)
9Audio Input (2EA)
10SDPIF out (1EA)SPDIF outSome models(LD21A,LD21C) are not supported.
11Earphone out (1EA)
12USB (1EA or 2EA)
13DVB
14Ethernet (1EA)DLNA(Wired, DMP only)Some models (LD21A,LD21C) are not supported.
This specification sheet is applied to all of the LCD TV with
LD21C chassis.
2. Designation
(1) The adjustment is according to the order which is designated
and which must be followed, according to the plan
can be changed only on agreeing.
(2) Power adjustment : Free Voltage.
(3) Magnetic Field Condition: Nil.
(4) Input signal Unit: Product Specification Standard.
(5) Reserve after operation : Above 5 Minutes (Heat Run)
Temperature : at 25 °C ± 5 °C
Relative humidity : 65 ± 10 %
Input voltage : 220 V, 60 Hz
(6) Adjustment equipments: Color Analyzer(CA-210 or CA-110),
DDC Adjustment Jig, Service remote control.
(7) Push the "IN STOP" key - For memory initialization.
Case1 : Software version up
1. After downloading S/W by USB , TV set will reboot
automatically.
2. Push “In-stop” key.
3. Push “Power on” key.
4. Function inspection
5. After function inspection, Push “In-stop” key.
Case2 : Function check at the assembly line
1. When TV set is entering on the assembly line, Push
“In-stop” key at rst.
2. Push “Power on” key for turning it on.
→ If you push “Power on” key, TV set will recover
channel information by itself.
3. After function inspection, Push “In-stop” key.
3. Main PCB check process
▪ APC - After Manual-Insert, executing APC
* Boot file Download
(1) Execute ISP program "Mstar ISP Utility" and then click
"Config" tab.
(2) Set as below, and then click "Auto Detect" and check "OK"
message.
If "Error" is displayed, check connection between computer,
jig, and set.
(3) Click "Read" tab, and then load download file(XXXX.bin)
by clicking "Read"
(1)
filexxx.bin
which
(4) Click "Connect" tab. If "Can't" is displayed, check connection
between computer, jig, and set.
(2)
(3)
Please Check the Speed :
To use speed between
from 200KHz to 400KHz
(5) Click "Auto" tab and set as below.
(6) Click "Run".
(7) After downloading, check "OK" message.
(4)
filexxx.bin
(5)
(7)...........OK
(6)
* USB DOWNLOAD
(1) Put the USB Stick to the USB socket.
(2) Automatically detecting update file in USB Stick.
- If your downloaded program version in USB Stick is Low,
it didn't work. But your downloaded version is High, USB
data is automatically detecting.
(3) Show the message "Copying files from memory".
(4) Updating is starting.
(5) Updating Completed, The TV will restart automatically.
(6) If your TV is turned on, check your updated version and
Tool option. (explain the Tool option, next stage)
* If downloading version is more high than your TV have, TV
can lost all channel data. In this case, you have to channel
recover. if all channel data is cleared, you didn’t have a DTV/
ATV test on production line.
Only for training and service purposes
* After downloading, have to adjust Tool Option again.
- 10 -
(1) Push "IN-START" key in service remote control.
(2) Select "Tool Option 1" and push "OK" key.
(3) Punch in the number. (Each model has their number)
4) RGB (PC : 1024 x 768 @ 60hz) (* RGB input : LD21B
only support)
5) HDMI
6) PC Audio In (* except LD21A chassis model)
* Display and Sound check is executed by Remote control.
* Auto-control interface and directions
(1) Adjust in the place where the influx of light like floodlight
around is blocked. (illumination is less than 10 lux).
(2) Adhere closely the Color analyzer(CA210) to the module
less than 10 cm distance, keep it with the surface of the
Module and Color analyzer's prove vertically.(80° ~ 100°).
(3) Aging time
- After aging start, keep the power on (no suspension of
power supply) and heat-run over 5 minutes.
- Using 'no signal' or 'POWER ONLY' or the others, check
the back light on.
<Caution>
Not to push the INSTOP key after completion if the function
inspection.
4. Total Assembly line process
4.1. Adjustment Preparation
▪ W/B Equipment condition
CA210
: CCFL/EEFL -> CH9, Test signal: Inner pattern(80IRE)
LED -> CH14, Test signal: Inner pattern(80IRE)
▪ If it is executed W/B adjustment in 2~3 minutes H/run, it is
adjusted by Target data
ModeTempCoordinate specTarget
Cool13,000k
Medium9,300k
Warm6,500k
X=0.269 (±0.002)
Y=0.273 (±0.002)
X=0.285 (±0.002)
Y=0.293 (±0.002)
X=0.313 (±0.002)
Y=0.329 (±0.002)
* Connecting picture of the measuring instrument
(On Automatic control)
Inside PATTERN is used when W/B is controlled. Connect to
auto controller or push Adjustment R/C POWER ON →
Enter the mode of White-Balance, the pattern will come out.
Full White Pattern
RS-232C Communication
X=0.271
Y=0.276
X=0.287
Y=0.296
X=0.315
Y=0.332
LAMP
<Test Signal>
Inner pattern
(204gray,
80IRE)
CA-210
COLOR
ANALYZER
TYPE : CA-210
▪ Auto adjustment Map(using RS-232C to USB cable)
RS-232C COMMAND
[CMD ID DATA]
Wb 00 00 White Balance Start
Wb 00 ff White Balance End
RS-232C COMMAND
[CMD ID DATA]
MIN
CENTER
(DEFAULT)
MAX
CoolMidWarmCool Mid Warm
R Gain jgJajd00172192 192192
G Gain jhJbje00172192 192192
B Gain jiJcjf00192192 172192
R Cut646464128
G Cut646464128
B Cut646464128
<Caution>
Color Temperature : COOL, Medium, Warm.
One of R Gain/G Gain/ B Gain should be kept on 0xC0, and
adjust other two lower than C0.(When R/G/B Gain are all
C0, it is the FULL Dynamic Range of Module)
* Manual W/B process using adjust Remote control.
▪ After enter Service Mode by pushing "ADJ" key,
▪ Enter White Balance by pushing "►" key at "8. White
* After you finished all adjustments, Press "In-start" key and
compare Tool option and Area option value with its BOM, if
it is correctly same then unplug the AC cable. If it is not
same, then correct it same with BOM and unplug AC cable.
For correct it to the model's module from factory Jig model.
* Push the "IN STOP" key after completing the function
inspection. And Mechanical Power Switch must be set
“ON”.
- Check the POWER cable and SIGNAL cable insertion condition
5.2. HI-POT auto-check
(1) Pallet moves in the station. (POWER CORD / AV CORD is
tightly inserted)
(2) Connect the AV JACK Tester.
(3) Controller (GWS103-4) on.
(4) HI-POT test (Auto)
- If Test is failed, Buzzer operates.
- If Test is passed, GOOD Lamp on and move to next process automatically.
5.3. Checkpoint
(1) Test voltage
- Touchable Metal : 3KV / min at 100mA
- SIGNAL : 3KV / min at 100mA
(2) TEST time: 1 second. (case : mass production )
(3) TEST POINT
- Touchable Metal => LIVE & NEUTRAL : Touchable Metal.
- SIGNAL => LIVE & NEUTRAL : SIGNAL.
6. Model name & Serial number D/L
▪ Press "Power on" key of service remote control.
(Baud rate : 115200 bps)
▪ Connect RS232 Signal Cable to RS-232 Jack.
▪ Write Serial number by use RS-232.
▪ Must check the serial number at the Product/Service info..
(menu key -> red key -> select product/Service info)
6.2. Comand Set
Adjust modeCMD(hex)LENGTH(hex)Description
EEPROM WRITEA0h84h+nn-bytes Write (n = 1~16)
* Description
FOS Default write : <7mode data> write
Vtotal, V_Frequency, Sync_Polarity, Htotal, Hstart, Vstart, 0,
Phase
Data write : Model Name and Serial Number write in EEPROM,.
6.3. Method & notice
(1) Serial number D/L is using of scan equipment.
(2) Sett ing of scan equ ipm ent operated by Manufac turing
Technology Group.
(3) Serial number D/L must be conformed when it is produced in
production line, because serial number D/L is mandatory by
D-book 4.0.
* Manual Download(Model Name and Serial Number)
If the TV set is downloaded by OTA or Service man, sometimes
model name or serial number is initialized.(Not always)
There is impossible to download by bar code scan, so It need
Manual download.
1) Press the "Instart" key of Adjustment remote control.
2) Go to the menu "6.Model Number D/L" like below photo.
3) Input the Factory model name or Serial number like photo.
6.1. Signal Table
CMDLENGTHADHADLDATA_1. . .Data_nCSDELAY
CMD : A0h
LENGTH : 85~94h (1~16 bytes)
ADH : EEPROM Sub Address high (00~1F)
ADL : EEPROM Sub Address low (00~FF)
Data : Write data
CS : CMD + LENGTH + ADH + ADL + Data_1 +...+ Data_n
Delay : 20ms
4) Check the model name Instart menu. → Factory name displayed.
(ex 32LV3400-ZG)
5) Check the Diagnostics.(DTV country only) → Buyer model
displayed.(ex 32LV3400-ZG)
▪ Play file : Serial.exe
▪ MAC Address edit
▪ Input Start / End MAC address
7.1.2 Download method
(1) Communication Prot connection
Connection : PCBA (USB Port) → USB to Serial Adapter
(UC-232A) → RS-232C cable → PC(RS-232C port)
* Caution : LJ21* chassis support only UC-232A driver. (only
use this one. )
(2) MAC Address & CI+ Key Download
▪ Set CI+ Key path Directory at Start Mac & CI+ Download
Programme
▪ Com 1,2,3,4 and 115200(Baudrate)
7.2 LAN Inspection
7.2.1. Equipment & Condition
▪ Each other connection to LAN Port of IP Hub and Jig
7.2.2. LAN inspection solution
▪ LAN Port connection with PCB
▪ Network setting at MENU Mode of TV
▪ Setting automatic IP
▪ Setting state confirmation
-> If automatic setting is finished, you confirm IP and MAC
Address.
GP4_LOW
▪ Port connection button click(1)
▪ Push the (2) MAC Address write.
▪ At success Download, check the OK (3).
▪ Start CI+ Key Download, Push the (4).
▪ Check the OK or NG.
7.3. LAN PORT INSPECTION(PING TEST)
Connect SET -> LAN port == PC -> LAN Port
SETPC
7.3.1. Equipment setting
(1) Play the LAN Port Test PROGRAM.
(2) Input IP set up for an inspection to Test Program.
*IP Number : 12.12.2.2
7.3.2. LAN PORT inspection (PING TEST)
(1) Play the LAN Port Test Program.
(2) Connect each other LAN Port Jack.
(3) Play Test (F9) button and confirm OK Message.
(4) Remove LAN cable.