LG 3D 55LN5400 – LG 55LN5400 TA – Service mode and adjustments and Check procedure

NB:  The repair to this TV should be done at the authorized service center for LG.  Not all local service centers won’t have enough testing instruments to repair this TV

Please do not attempt to repair this TV; if you're not well aware in electronics.

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 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 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 non-abrasive applicator; 10 % (by volume) Acetone and 90 % (by volume) isopropyl alcohol (90 % - 99 % strength)
CAUTION: This is an inflamable mixture.  Unless specified 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 fixtures specified here.
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 commonly are called Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some feld-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 classified as “anti-static” can generate electrical charges suffcient 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 harmless motion such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity suffcient 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, suctiontype 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 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.

IC 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 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).

Small-Signal" Discrete Transistor Removal/Replacement

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.

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 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.

This specification details is applied to all of the LED TV with LB36B chassis.

Case-1

Software version up

After downloading S/W by USB, TV set will reboot automatically

Push the “In-Stop” key [at the service remote controller.

[ You should have a "SERVICE REMOTE CONTROL" to do anything regard service adjustments with the  service adjustments.  It cannot be done with the user remote control.  To buy an LG service remote control; contact any service department for LG.  They only can provide it to you. Push the ‘Power ON’ key.

Function inspection.

After function inspection, push the ‘In stop” key.

Case-2

Function check at the assembly line.

When TV set is entering on the assembly line, Push the ‘In Stop” key first.

Push the ‘Power’ key for turn it ON.

[if you push the power-on key, Set will recover channel information by itself.]

After cunction inspection, push the ‘In-stop] key.

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"

(4) Click "Connect" tab. If "Can't" is displayed, check connection between computer, jig, and set

(5) Click "Auto" tab and set as below.

(6) Click "Run".

(7) After downloading, check "OK" message.

USB DOWNLOAD(*.epk file download)

(1) Put the USB Stick to the USB socket.

(2) Automatically detecting update file in USB Stick.  

* If version of update file in USB Stick is lower, it will not work. But version of update file is higher, USB data will be detected automatically.

(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 updated version is higher than what TV has, the 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.

After downloading, have to adjust Tool Option again.
(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) Completed selecting Tool option.

RS-232C Connection Method.
Connection : PCBA (USB Port) > USB to Serial Adapter (UC-232A) > RS-232C cable > PC(RS-232C port)
Product name of USB to Serial Adapter is UC-232A.

ADC Process

- Enter Service Mode by pushing "ADJ" key,

- Enter Internal ADC mode by pushing "►" key at "8. ADC Calibration". 

Caution: Using "P-ONLY" key of the Adjustment remote control, power on TV.

Adjust Sequence

▪ aa 00 00 [Enter Adjust Mode]

▪ xb 00 40 [Component1 Input (480i)]

▪ ad 00 10 [Adjust 480i Comp1]

▪ xb 00 60 [RGB Input (1024*768)]

▪ ad 00 10 [Adjust 1024*768 RGB]

▪ aa 00 90 End Adjust mode

* Required equipment : Adjustment remote control.

Function Check
Check display and sound.
Check Input and Signal items.
(1) TV
(2) AV (CVBS)
(3) COMPONENT (480i)
(4) HDMI
* Display and Sound check is executed by Remote control.

Caution:  DO Not to push the "INSTOP" key after completion if the function inspection.

Local Dimming Function Check
Step1) Turn on TV.
Step2) Press “P-only” key, enter to power only mode and escape the “P-only” Mode by pressing “Exit” key.
Step3) Press “Tilt” key, entrance to Local Dimming mode.
Step4) At the Local Dimming mode, module Edge Backlight moving Top to bottom Back light of module moving.
Step5) confirm the Local Dimming mode.
Step6) Press “Exit” key

3D function test
(Pattern Generator MSHG-600, MSPG-6100[Support HDMI1.4])
* HDMI mode No. 872 , pattern No.83
(1) Please input 3D test pattern like below.

(2) When 3D OSD appear automatically, then select OK button.

(3) Don't wear a 3D Glasses, check the 3rd picture like below.

EYE-Q function check
Step1) Turn on TV
Step 2) Press EYE key of Adj. R/C.
Step 3) Cover the Eye Q sensor on the front of the using your hand and wait for 6 seconds.
Step 4) Confirm that R/G/B value is lower than 10 of the “Raw Data(Sensor data, Back light)”. If after 6 seconds, R/G/ B value is not lower than 10, replace Eye Q sensor
Step 5) Remove your hand from the Eye Q sensor and wait for 6 seconds.
Step 6) Confirm that “ok” pop up. If change is not seen, replace Eye Q sensor.

NB:  The repair to this TV should be done at the authorized service center for LG.  Not all local service centers won’t have enough testing instruments to repair this TV

Please do not attempt to repair this TV; if you're not well aware in electronics.