REPAIRING AND NOT THROWING AWAY

REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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Thursday, 31 December 2020

REPAIRING / SERVICING TV LG 43UK6450PLC

Technical description and composition of LG 43UK6450PLC TV, type of panel and modules used. Module composition.

LG LED
Model: 43UK6450PLC 43UK6450

Chassis/Version: LJ8 Chassis

Panel: AC430DGG-SLEM1

LED backlight: LC43490086A

LED driver (backlight): integrated into MainBoard

PWM LED driver: LC5910

MOSFET LED driver: KF9N25

Power Supply (PSU): EAX67209001 LGP43DJ-17U1

PWM Power: PFC, PWM

MOSFET Power: TO-252

MainBoard: EAX67872805 (1.1) EBU65273804

IC MainBoard: CPU, eMMC, DRAM, AUDIO, DC/DC

TDJA-G601D

Specifications 43UK6450
LG 43UK6450PLC
General advice about LCD LED TV repair
Possible malfunctions

- LG 43UK6450PLC TV does not turn on. There are no indications of operation. The indicators on the front panel are not lit or blinking, the TV does not respond to the control buttons.

In such cases the main problem is the power supply module EAX67209001. If there are no necessary supply voltages in the converters secondary circuits, check the power switches (TO-252) and rectifier diodes for possible partial or complete breakdown.
If there is a breakdown in the secondary circuits, the inverter can usually be short-circuited, and a short in the power elements of the primary circuit will usually blow the mains fuse.
Mos-Fet power switches used in switching power supplies sometimes fail due to the failure of any other elements that can take it out of key mode, or create an exceedance of the maximum allowable parameters of the switch. These can be the elements that feed the PWM controller, the frequency or damping circuits, or the negative feedback elements in the stabilization circuit. PFC, PWM controllers, if there is no visible damage or outright short circuits between pins, are checked by replacing with new or known good ones.

- No picture, sound is present, and the remote control responds. Or the image can appear for a second and then disappear at once.

Often in such cases there is no backlighting of the LED panel. Often the reason is a faulty LED (breakage, short circuit...), or connectors of strips LC43490086A, less often faulty is the LED-driver.
To check the LED strips for breakage without disassembling the panel can help, for example, a power source. It is not possible to open the series connected PN-junctions with a simple multimeter, you will need a voltage of about several tens of volts.

- Indicator blinks or lights constantly, the TV set doesn't turn on, the remote doesn't respond.

Repair or diagnostic of motherboard EAX67872805 should be started with checking stabilizers and power converters needed to power the chips and matrix. If necessary, software (software) should be updated or replaced. In cases of complicated MB (SSB) repairs and with the necessary skills and equipment it may sometimes be necessary to replace its CPU, eMMC, DRAM, AUDIO, DC/DC chips and other possible defective components. BGA soldering problems are usually easy to diagnose with the heating method.

Before replacing the TDJA-G601D tuner if there is no tuning to the channels you must first check the software and the power supply voltages on its outputs. Also make sure that the tuner and the processor can communicate via the I2C bus.

Warning. I strongly recommend for the users and owners of TV sets 43UK6450PLC, having no qualification, knowledge and experience not to try to do the repair works themselves in order to avoid the negative consequences which can lead to the complete uselessness of the device.

Restriction of the driver current after the replacement of the backlighting strips (violet glow, phosphor crumbling). Wizard's comments.

You can reduce the backlight current from 660 mA to 380 mA by replacing the 0.8 Ohm current sense resistor with a 1.2 Ohm current sense resistor at the source of the switch.
Backlight driver current limitation. LC5910. General recommendations.

To reduce the backlight current in LED drivers with the LC5910 step-down controller, you can increase the current sensor resistance at the source of the converter's power switch proportionally.



DOWNLOAD SCHEMATIC DIAGRAM  BACKLIGHT DRIVER   ------------------>    LC5910S

The appearance of the MainBoard EAX67872805 is shown in the figure below:

EAX67872805

MainBoard Appearance

The main features of the LG 43UK6450PLC:

The matrix (LED panel) AC430DGG-SLEM1 is installed.
To power the backlight LEDs is used a converter, combined with the main board EAX67872805, controlled by a PWM controller LC5910. KF9N25 type switches are used as power elements of LED-driver.
 

 

 


Necessary supply voltages for all LG 43UK6450PLC TV nodes are generated by EAX67209001 power supply module or its analogues using PFC, PWM and TO-252 type power keys.
MainBoard - the main board (motherboard) is EAX67872805 module, using CPU, eMMC, DRAM, AUDIO, DC/DC and other chips.
The TDJA-G601D tuner provides TV program reception and channel tuning.


Instructions and updates

There are downloadable files for the 43UK6450PLC model from the manufacturer:

Update and instruction files:
File Description File Name Type Date Size
SW File (Version 05.20.15) . TV_Software_Update_Guide_v3.pdf PDF 11.11.2020 2014K update instructions
SW File (Version 05.20.15) . Firmware (USB) Software_File(Version_05.20.15).zip zip 11.11.2020 884809K
Compatible with 43UK6200PLA, 43UK6300LLB, 43UK6300MLB, 43UK6300PLB, 43UK6390PLG, 43UK6400PLF, 43UK6450PLC, 43UK6470PLC, 43UK6500LLA, 43UK6500MLA, 43UK6500PLA, 43UK6510PLB, 43UK6550PLD, 43UK6710PLB, 43UK6750PLD, 43UK6950PLB, 49UK6200PLA, 49UK6300MLB, 49UK6300PLB, 49UK6390PLG, 49UK6400PLF, 49UK6450PLC, 49UK6470PLC, 49UK7500PLC, 49UK7550LLA, 49UK7550MLA, 49UK7550PLA, 50UK6300LLB, 50UK6300MLB, 50UK6300PLB, 50UK6410PLC, 50UK6470PLC, 50UK6500LLA, 50UK6500MLA, 50UK6500PLA, 50UK6510PLB, 50UK6710PLB, 50UK6750PLD, 50UK6950PLB, 55UK6200PLA, 55UK6300LLB, 55UK6300MLB, 55UK6300PLB, 55UK6400PLF, 55UK6470PLC, 55UK6500LLA, 55UK6500MLA, 55UK6500PLA, 55UK6510PLB, 55UK6550PLD, 55UK6710PLB, 55UK6750PLD, 55UK6950PLB, 55UK7500PLC, 55UK7550LLA, 55UK7550MLA, 55UK7550PLA, 60UK6200PLA, 65UK6300LLB, 65UK6300MLB, 65UK6300PLB, 65UK6400PLF, 65UK6450PLC, 65UK6470PLC, 65UK6500MLA, 65UK6500PLA, 65UK6710PLB, 65UK6750PLD, 65UK6950PLB, 65UK7550LLA, 65UK7550MLA, 65UK7550PLA, 70UK6500PLB, 70UK6710PLA, 70UK6950PLA, 75UK6200PLB, 75UK6500PLA, 75UK6750PLB.

Manuals and User Manuals:
Document Language Date Size
Quick start guide English - English 10.07.2020 6308K
Quick Start Guide English - English,Estonian,Latvian,Lettish,Lithuanian,Russian 07.14.2020 55 963K
Quick guide English - English,Estonian,Latvian,Lettish,Lithuanian,Russian 07.14.2020 No data

You can download the files for the model 43UK6450PLC from the manufacturer's website.


LG 43UK6450 LCD TV with AC430DGG-SLEM1, 42.5" (108 cm) diagonal, 16:9 aspect ratio. The required brightness of 250 cd/m² screen luminescence is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum brightness, is 1300:1. The LCD panel implements the principle of direct display backlighting with the rear positioning of the LEDs - Direct LED.
AC430DGG-SLEM1 matrix and MainBoard software EAX67872805 are able to realize the image in the highest quality UHD at 3840x2160 pixels in 4K UHD, HDR standard. Image processing is made by modern technology High Dynamic Range (HDR) with an extended range of brightness gradation.
The model of TV 43UK6450 has built-in software (software) SMART and installed the operating system webOS. Connection to the network can be made via Wi-Fi wireless connection. Supported media formats: MP3, WMA, MPEG4, HEVC (H.265), DivX, MKV, JPEG.
The sound speaker system has a capacity of 20 W (2x10 W) and is equipped with two loudspeakers. NICAM stereo sound processing system and Sound Surround surround function are used.
Communication with other devices via an external interface is supported by standard inputs and outputs: antenna input (RF), AV, component, HDMI x4, USB x2, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11ac, Miracast. The digital tuner is capable of receiving TV channels in DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The TV uses the EAX67209001 power supply.

Overall dimensions: with stand 977x636x224mm, without stand 977x575x81mm.

TV weight: with stand: 9.3 kg, without stand: 8.3 kg.

Warning. Panel AC430DGG-SLEM1 of LG 43UK6450 LED TV is an expensive and unreliable element of the TV.
Do not allow any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
Also it is not safe to get liquid on the screen. Sometimes one drop is enough if it drips down the glass onto the cables and the TV becomes unrepairable.

Posted By: FRANK at 01:37
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