SAMSUNG LED
Model: UE43NU7170U UE43NU7170
Chassis / Version: BN41-02635A
Panel: CY-NN043HGAV2V
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): BN44-00947A L40E6_NDY
PWM Power: PFC, PWM
MOSFET Power: N-FET TO-220F
MainBoard: BN41-02635A BN94-12796E
IC MainBoard: CPU: SDP1711, EMMC: KLM4G1FETE, Audio: TAS5745
Tuner: BN40-00330B
Technical Specifications UE43NU7170U
SAMSUNG UE43NU7170U
General repair guidelines for TV LCD LED
Possible malfunctions
- SAMSUNG UE43NU7170U does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
In some of these cases, the main switching power supply, the BN44-00947A module, is faulty. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches (N-FET TO-220F) and rectifier diodes for a possible partial or complete breakdown.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) PFC, PWM, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- 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.
The most likely in these cases is a malfunction of the LED backlight. Usually the cause of the malfunction is in the breakage of the LEDs, or in the connectors of the LED strips, but sometimes the LED driver also turns out to be faulty.
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, you can sometimes 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 TV does not turn on, the indicator signals standby or working mode, or blinks.
Repair or diagnostics of the BN41-02635A motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, you should update or replace the software (software). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the CPU elements: SDP1711, EMMC: KLM4G1FETE, Audio: TAS5745. BGA chip malfunctions are usually easy to detect by warming up.
Before replacing the BN40-00330B tuner, if there is no tuning to the channels, first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair to professionals with sufficient experience in the repair of electronic equipment.
The appearance of the MainBoard BN41-02635A is shown in the figure below:BN41-02635A
The appearance of the power supply
Main features of the SAMSUNG UE43NU7170U device:
Installed matrix (LED-panel) CY-NN043HGAV2V.
To power the backlight LEDs, a converter is used, combined with the main board BN41-02635A.
The necessary supply voltages for all nodes of the SAMSUNG UE43NU7170U TV are generated by the BN44-00947A power supply module or its analogs using PFC, PWM microcircuits, and N-FET TO-220F type power switches.
MainBoard - the main board (motherboard) is a BN41-02635A module, using CPU chips: SDP1711, EMMC: KLM4G1FETE, Audio: TAS5745 and others.
The tuner BN40-00330B provides the reception of television programs and tuning to channels.