
SAMSUNG LED
Model: UE40F8000 UE40F8000AT
Panel: CY-KF400DSLV1V
LED backlight: 3D-7032LED-R / L V3LE-400SMB-R3 (01/13/22)
T-CON: LSF400HL01 BN41-01939C
LED driver (backlight): integrated into PSU; 71V 295mA, 158V 442mA
Power Supply (PSU): BN44-00635A
PWM Power: SEM3110A, 2A153D (Standby)
MainBoard: BN41-01959C BN94-06618P
IC MainBoard: SN1202033 (TSSOP32), EEPROM: 24C512, SOUND: NTP-7412S, DRAM: K4B4G1646B
Tuner: BN40-00267A
Control: Wi-Fi: BN59-01161A
Technical Specifications UE40F8000
SAMSUNG UE40F8000
General repair guidelines for TV LCD LED
Possible malfunctions
- SAMSUNG UE40F8000 TV does not turn on. There are no signs of operability. The indicators on the front panel do not shine and do not blink, and the remote control and control buttons do not respond.
In such cases, the fault should be sought first in the BN44-00635A power supply module. It is necessary to verify the presence of secondary voltages and, if they are absent, check the power switches and rectifier diodes for a possible short circuit.
In case of breakdowns in the secondary circuits, the converter can emergencyly operate in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM chip SEM3110A, 2A153D (Standby) can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
Often in such cases, there is no LED backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source. By opening the panel, each LED can be checked separately. Usually, Chinese multimeters light up a single 3-volt LED, if you connect probes in the forward direction to it. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as a health indicator. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the BN41-01959C 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). In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its chips SN1202033 (TSSOP32), EEPROM: 24C512, SOUND: NTP-7412S, DRAM: K4B4G1646B and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
The malfunction of the tuner BN40-00267A is established after checking the software and all supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
It should be remembered! Attempts to self-repair a SAMSUNG UE40F8000 TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!

BN41-01959C
BN41-01959C can be used in TVs:
SAMSUNG UE55F8000AT (Panel CY-KF550DSLV5V), SAMSUNG UE40F8000 UE40F8000AT (Panel CY-KF400DSLV1V).
The appearance of the power supply
Main features of the SAMSUNG UE40F8000 device:
Installed matrix (LED-panel) CY-KF400DSLV1V.
The matrix control uses the Timing Controller (T-CON) LSF400HL01.
To power the backlight LEDs, a converter is used, combined with a power supply.
The necessary supply voltages for all nodes of the SAMSUNG UE40F8000 TV are generated by the BN44-00635A power module or its analogs using SEM3110A, 2A153D (Standby) microcircuits.
MainBoard - the main board (motherboard) is a BN41-01959C module using SN1202033 (TSSOP32) chips, EEPROM: 24C512, SOUND: NTP-7412S, DRAM: K4B4G1646B and others.
The tuner BN40-00267A provides the reception of television programs and tuning to channels.