REPAIRING / SERVICING TV SAMSUNG UE40NU7100U

Technical description and composition of the SAMSUNG UE40NU7100U TV, type of panel and modules used. Module composition.

SAMSUNG LED
Model: UE40NU7100U

Chassis/Version: FA01

Panel: CY-NN040HGLV2V

LED backlight: LM41-00550A, BN61-15481X

LED driver (backlight): integrated into PSU

PWM LED driver: BD94062F

MOSFET LED driver: TO-252

Power Supply (PSU): BN44-00947A L40E6_NDY

PWM Power: PFC, PWM

MOSFET Power: N-FET TO-220F

MainBoard: BN41-02635B BN94-13264E

IC MainBoard: CPU, eMMC: KLM4G1FEPD, SPI 25Q40, EEPROM: 24C512, DRAM, AUDIO: TAS5749M

Tag: BN40-00331A

Specifications UE40NU7100U
SAMSUNG UE40NU7100U
General recommendations for LCD LED TV repair
Possible defects

- SAMSUNG UE40NU7100U does not turn on, the indicators on the front panel are not lit or blinking. TV does not respond to the control buttons and remote control.

In such cases the problem should be looked for in the circuits of the power supply BN44-00947A. It is necessary to measure the output voltages in its secondary circuits, and in case of their complete absence check the serviceability of the power switches (N-FET TO-220F) and the rectifier diodes for possible breakdown (short circuit).
At breakdown of semiconductors in the secondary circuits of any converter, as a rule, it can operate in the short-circuit emergency mode without output voltages, and at short circuit in the elements of the primary circuit most often the line fuse and more rarely the current sensor at the source of the switch break down at once.
Mos-Fet switches used in switched-mode power supplies usually fail due to the failure of other elements, which can take it out of key mode, or cause it to exceed the maximum current or voltage. These may be the circuits feeding the PWM controller, the damping or frequency-retaining circuits, or the negative feedback elements in the stabilization circuit. PWM controllers (PFC) PFC, PWM, if there is no external damage and short circuit between the pins, are checked by replacing with known good ones.

- No picture, the screen is black, there is sound, with the external screen light you can sometimes see faintly visible outlines of the image.

Often in such cases there is no backlight of LED panel. Often the reason is a failure of LEDs (breakage, short circuit...), or connectors of LM41-00550A, BN61-15481X, less often faulty is the LED-driver.
To detect breakage in the LED strips without disassembling the panel you will need a power source. Open transitions connected in series can not be done with a simple multimeter, you need a voltage of several tens of volts.

- Indicator is blinking or glowing all the time, TV set doesn't turn on, remote control doesn't respond.

Repair or diagnosis of the motherboard BN41-02635B should begin with checking the stabilizers and power converters needed to power the chips and matrix. If necessary, the software (software) should be updated or replaced. When repairing the MB board, you must check its components CPU, eMMC: KLM4G1FEPD, SPI 25Q40, EEPROM: 24C512, DRAM, AUDIO: TAS5749M. Defective elements should be replaced. If the chips with BGA soldering technology are used, the problem in its implementation is detected by the method of local heating of the chip.

If you suspect the BN40-00331A tuner malfunction, first of all make sure that the software is correct, as well as that the required supply voltages and pulses of data exchange with the CPU via the I2C bus are present at the respective pins of the tuner.

It is necessary to remember! Attempts to repair TV SAMSUNG UE40NU7100U by yourself, in the absence of the necessary skills and experience, is strongly not recommended and is fraught with negative consequences, up to the complete unrepairable device!

More on MainBoard Repair

The exterior of the MainBoard BN41-02635B is shown in the illustration below:

BN41-02635B

MainBoard Appearance

The main features of the SAMSUNG UE40NU7100U:

A matrix (LED panel) CY-NN040HGLV2V is installed.
To power the LED backlight the converter is used, combined with the power supply, controlled by the PWM controller BD94062F. As the power elements of LED-driver are used switches of TO-252 type.
The power supply module BN44-00947A 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 UE40NU7100U TV assemblies.


MainBoard - the main board (motherboard) is a module BN41-02635B, using CPU chips, eMMC: KLM4G1FEPD, SPI 25Q40, EEPROM: 24C512, DRAM, AUDIO: TAS5749M and others.
The BN40-00331A tuner provides TV program reception and channel tuning.


Instructions and updates

There are download files for UN40NU7100FXZC from the manufacturer:

Latest software updates, firmwares (latest firmwares):
File type File name Version Date Size
Update instructions 2018_TV_Firmware_Upgrade_Instruction_T-KTM2LDEUC.pdf 1.0 23.06.2020 0.5 Mb
Update file (USB) T-KTM2LDEUC.zip 1310.4 02.11.2020 1117.74 Mb
Update file (USB) T-KTM2LDEUC_1310.4.exe 1310.4 02.11.2020 1117.49 Mb

Instruction manuals and User Manuals:
File Type File Name Version Date Size
User manual BN68-08987G-02_UNU7100X_RU_L02_180710.1.pdf 02 13.07.2018 1.22 Mb
BN68-08995L-01_QSG_UNU7100X_CIS_180314.0.pdf 01 23.05.2018 0.3 Mb
Instruction PDF ENG_KM2DVBEUN-3.0.2_181205.0.0.pdf 3.0.2 02.01.2019 11.33 Mb

You can download the files from the manufacturer's website for the model UN40NU7100FXZC


SAMSUNG UE40NU7100U LCD TV CY-NN040HGLV2V, 40" (102 cm) diagonal in 16:9 aspect ratio. This model uses a panel with an end arrangement of LEDs in the backlighting of the display - Edge LED.
Matrix CY-NN040HGLV2V and MainBoard software BN41-02635B able to realize the image in the highest quality UHD at 3840x2160 pixels in 4K UHD, HDR. Image processing is made by modern technology High Dynamic Range (HDR) with an extended range of brightness gradation.
The UE40NU7100U has built-in SMART software and Tizen Operating System. Connection to the network can be made via Wi-Fi wireless connection. Supported formats of multimedia files: 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 x3, USB x2, Ethernet (RJ-45), Wi-Fi 802.11ac, Miracast. The digital tuner is capable of receiving DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 TV channels.

The power consumption in mains mode is 105 W. Power supply BN44-00947A.

Overall dimensions: with stand 914x604x210 mm, without stand 914x532x59 mm.

TV weight: with stand: 8.8 kg, without stand: 8.6 kg.

Warning. The panel CY-NN040HGLV2V of the SAMSUNG UE40NU7100U LED TV is an expensive and unreliable part of it.
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.