Technical description and composition of the SAMSUNG UE55NU8070U TV, panel type and applicable modules. The composition of the modules.SAMSUNG LED
Model: UE55NU8070U
Chassis / Version: FB04
Panel: CY-SN055FLLV4V
LED driver (backlight): integrated into PSU
Power Supply (PSU): BN44-00878C REV1.2 PSLF181E10A L55E7R_NSM
PWM Power: PFC, PWM
MainBoard: BN41-02636A BN94-12926J
IC MainBoard: CPU, eMMC, DRAM, AUDIO, DC / DC
Tuner: DVB-T2 & SAT
Technical Specifications UE55NU8070U
SAMSUNG UE55NU8070U
General repair guidelines for TV LCD LED
Possible malfunctions
- SAMSUNG UE55NU8070U TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
Failure in such cases should begin to be sought in the power supply circuits of BN44-00878C. Then we recommend that you measure its output voltages and, if they are absent, you should check the health of the power switches and rectifier diodes of the converters for a probable short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the elements of the primary circuit, the mains fuse usually breaks.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback circuits (OOS) of stabilization. PWM controllers (PWM) PFC, PWM, if they do not have visible damage to the case and open fault between the terminals, are usually checked by replacement.
- There is no image, but there is sound and all other functions work. Sometimes when you turn on the image for a second appears and disappears.
As a rule, in such cases there is no display backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To check the LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, sometimes you can detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the BN41-02636A motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Often, the MB (SSB) card needs to be replaced in case of complex faults that are difficult to detect. When trying to repair, you should check its elements - CPU, eMMC, DRAM, AUDIO, DC / DC and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
If there is no reception of television channels, but the TV works properly from external devices, first of all, check the voltage of the DVB-T2 & SAT tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Once again, remind users! Attempts to self-repair a SAMSUNG UE55NU8070U TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
The appearance of the MainBoard BN41-02636A is shown in the figure below:BN41-02636A
Main features of the SAMSUNG UE55NU8070U device:
Installed matrix (LED panel) CY-SN055FLLV4V.
To power the backlight LEDs, a converter is used, combined with a power supply.
The formation of the necessary supply voltages for all nodes of the SAMSUNG UE55NU8070U TV is carried out by the BN44-00878C power supply module, or its analogs using PFC, PWM chips.
MainBoard - the main board (motherboard) is a BN41-02636A module, using CPU, eMMC, DRAM, AUDIO, DC / DC, and others.
The DVB-T2 & SAT tuner allows you to receive television programs and tune to channels.
