Friday, 15 January 2021

REPAIRING / SERVICING TV SAMSUNG UE48H8000AT

Technical description and composition of the SAMSUNG UE48H8000AT TV, type of panel and modules used. Module composition.

SAMSUNG LED
Model: UE48H8000AT

Chassis/Version: TD01

Panel: CY-VH048DSLV1V

T-CON: BN41-02112A LSF480HQ02

LED driver (backlight): integrated into PSU

PWM LED driver: SOP-28

MOSFET LED driver: TO-252

Power Supply (PSU): BN44-00727A L55C2Q_EDY

PWM Power: PFC & PWM

MOSFET Power: N-FET TO-220F

MainBoard: BN41-02189A

IC MainBoard: STB: WT61P807, DRAM: K4B4G1646D-BCK0, Audio: TAS5747

TG: BN40-00278A

Specifications UE48H8000
SAMSUNG UE48H8000AT
General recommendations for LCD LED TV repair
Possible defects

- SAMSUNG UE48H8000AT TV does not turn on, does not respond to the remote and the control panel buttons, the lights are not lit or blinking.

In some of these cases the main switching power supply - the BN44-00727A module - is defective. It is necessary to measure its output supply voltages, and if not, check the functionality of power switches (N-FET TO-220F) of converters and rectifier diodes for the probability of breakdown in the semiconductor PN-junctions.
With any breakdown of semiconductors in the secondary circuits, the inverter can usually operate normally in the emergency short-circuit mode. In this case there are no output voltages. And when a short circuit occurs in the power elements of the primary circuit, as a rule, the mains fuse and rarely the current sensor at the source of the switch break down.
Breakdown of Mos-Fet switches used in pulse sources is often caused by failures of other elements, for example, in PWM regulator power supply circuit, in frequency-retaining or damping circuits, as well as in the Negative Feedback Stabilization. PWM PFC & PWM chips are usually checked by replacing them with new or known good ones.

- No picture, sound, there is, remote control responds. Or immediately after switching on for a second the image may appear and then immediately disappear.

As a rule, in such cases there is no display backlight. The cause may be in the breakage of the backlight LEDs, in their power supply stabilization, or in the violation of the contact connections of the string connectors.
It is better to use a power supply with a maximum voltage of 200V to check if the LEDs are working properly. It is not recommended to use any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (9 volt) in P-N junction test mode. If you connect the red probe of the multimeter to the anode of the LED and the black to its cathode, then the 3 volt LED will light up slightly and in the opposite direction you will find the faulty junction of the stabilizer. The functionality of the PN junction is indirectly an indication of the functionality of the LED.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

 

- The TV set doesn't turn on, the LED indicates standby or operation mode, or blinks.


If SAMSUNG UE48H8000 has no picture, but there is sound, often the display backlight CY-VH048DSLV1H simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LCD panel CY-VH048DSLV1H - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard BN41-02189A also turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary to trace the passage of LVDS signals from the MainBoard BN41-02189A, as well as synchronizing signals to the loops with drivers, with an oscilloscope.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

Repair or diagnostic of the motherboard BN41-02189A should begin with checking the stabilizers and power converters needed to power the chips and matrix. Software (software) should be updated or replaced if necessary. Boards repair and chips replacement: STB: WT61P807, DRAM: K4B4G1646D-BCK0, Audio: TAS5747 are produced with necessary equipment and corresponding element base. Malfunctions associated with the use of soldering technology BGA processor can be localized by the method of heating.

Before replacing the tuner BN40-00278A if there is no tuning to the channels it is first necessary to check the software and the supply voltage on its outputs. Also make sure that the tuner and the processor can communicate via I2C bus.

Once again, users must be reminded! Trying to repair the SAMSUNG UE48H8000AT TV without the appropriate qualification and experience can lead to its complete unrepairability! 

AND THOSE IDIOTS  WANNABE ALSO HAVE TO DIE IN HELL TOGETHER WITH THEIR TVs   WHEN PERFORMING UNTRAINED  SELF TAUGHT REPAIR  LANDING TO UNSUCCESSFULL OR PARTIAL RESULTS  AND THEN FOR THAT BLAMING THE HIGHLY SPECIALIZED AND TRAINED TECHNICIANS............ WHO WORK FOR A LIIVING INSTEAD.... AND EVENTUALLY HELPED THEM FOR FREE REPAIRING THEIR GARBAGE TVs !


More on MainBoard repair

The exterior of the MainBoard BN41-02189A is shown in the figure below:



BN41-02189A

MainBoard Appearance

The main features of the SAMSUNG UE48H8000AT:

A matrix (LED panel) CY-VH048DSLV1V is installed.
Timing Controller (T-CON) BN41-02112A is used to control the matrix.
To power the backlight LEDs a converter combined with a power supply is used, which is controlled by a PWM controller SOP-28. As the power elements of LED-driver are used switches type TO-252.
The power supply module BN44-00727A or its analogues with the use of PFC & PWM chips and N-FET TO-220F type power keys form the necessary supply voltages for all the SAMSUNG UE48H8000AT TV assemblies.
MainBoard - the main board (motherboard) is BN41-02189A module, using STB: WT61P807, DRAM: K4B4G1646D-BCK0, Audio: TAS5747 and other microchips.
The BN40-00278A tuner allows you to receive TV programs and tune to channels.


Instructions and updates

There are files to download for the UE48H8000ATXMS  model from the manufacturer:

Latest software updates, firmware (latest firmwares):
File type File name Version Date Size
Firmware Update User Manual 2014_TV_Firmware_Upgrade_Instruction_T-GFPDEUC.pdf 1.0 21.11.2014 0.48 Mb
Update file (USB) T-GFPDEUC_1410.0.exe 1410.0 02.12.2019 1026.14 Mb

User Manuals and Instructions:
File type File name Version Date Size
User manual [ENG] GPDVBEUH-1.110-0919.pdf - 09.24.2014 5.61 Mb
Quick Start Guide [UH8000-RU] BN68-05841H-04L04-0829.pdf 1.0 02.09.2014 15.02 Mb
Multiroom Link Guide [Mutiroom_Link] ENG-0715.pdf - 09.24.2014 7.16 Mb
Installation Guide UH8000-QSG-BN68-05842A-01-0926.pdf 1.0 02.09.2015 2.25 Mb

Files can be downloaded from the manufacturer's website for the UE48H8000ATXMS  model.



SAMSUNG UE48H8000 TV with LCD CY-VH048DSLV1H, diagonal size 48 "(122 cm) 16: 9 format. The display technology of this model is implemented with LED backlighting.
There is support for 3D images with active (shutter) separation technology of the right and left channels.
The CY-VH048DSLV1H sensor and the MainBoard BN41-02189A software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD).
The UE48H8000 TV is equipped with SMART software, built-in applications and the ability to work on the Internet. The connection to the network can be carried out via Wi-Fi wireless connection. The input analog video signal is decoded in PAL, SECAM, NTSC systems. Graphic processing of a digital signal is carried out in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
Speaker power 20 W (2x10 W) is provided by two speakers. The NICAM stereo audio processing system and the Sound Surround function are used.
Communication with other devices via an external interface is supported by standard input and output connectors: antenna input (RF), AV, component, SCART, HDMI x4, USB x3, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11n. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is provided. This interface supports standard resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The power supply is BN44-00727A.

Dimensions: with stand 1079x672x237 mm, without stand 1079x626x79 mm.

TV weight: with stand: 14.7 kg, without stand: 13.2 kg.

Attention! Panel CY-VH048DSLV1H of SAMSUNG UE48H8000 LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.