
SAMSUNG LED
Model: UE55M5550AU UE55M5550
Chassis / Version: BN41-02575B
Panel: CY-KK055BGAV5V
LED backlight: BN61-13355A
T-CON: T550HVN08.3 CTRL BD 55T23-C0A
LED driver (backlight): integrated into PSU
Power Supply (PSU): BN44-00872D L55E1K_KSM
PWM Power: PFC, PWM
MOSFET Power: N-FET TO-220F
MainBoard: BN41-02575B BN94-11891E
IC MainBoard: CPU: SDP1604
Tuner: BN40-00331B
Technical Specifications UE55M5550AU
SAMSUNG UE55M5550AU
General repair guidelines for TV LCD LED
Possible manifestations of defects
- SAMSUNG UE55M5550AU TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
With such manifestations, the BN44-00872D power module usually fails. It is necessary to measure its output voltages and, in case of their absence, check the serviceability of power switches and rectifier diodes in the converters for possible breakdown.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM microcircuits are usually checked by replacement with new ones, or obviously working.
- 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 this case, the LED backlight turns out to be faulty. Often the cause is a malfunction of the LEDs (open circuit, short circuit ...), or the connectors of the strips (strings), less often the LED driver is malfunctioning.
It should be remembered that it is not possible to determine the open circuit in the LED lines without disassembling the panels with a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then it is necessary to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow you to open the LED in the forward direction or dual LEd are used, then the PN junction of the emergency zener diode can indirectly serve as a health indicator. In case of LED-a failure, the zener diode PN junction 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 BN41-02575B 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). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard - CPU: SDP1604. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
If the TV works normally from external devices, but does not tune into television channels, the tuner BN40-00331B may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention TV owners! Attempts to self-repair SAMSUNG UE55M5550AU are not recommended by the manufacturer and can lead to serious negative consequences!


BN41-02575B
The appearance of the power supply
Main features of the SAMSUNG UE55M5550AU device:
Installed matrix (LED panel) CY-KK055BGAV5V.
The matrix control uses the Timing Controller (T-CON) T550HVN08.3.
To power the backlight LEDs, a converter is used, combined with a power supply.
The necessary supply voltages for all nodes of the SAMSUNG UE55M5550AU TV are generated by the BN44-00872D power module or its analogs using PFC, PWM microcircuits, and N-FET TO-220F type power switches.
MainBoard - the main board (motherboard) is a BN41-02575B module, using CPU chips: SDP1604 and others.
The tuner BN40-00331B provides the reception of television programs and tuning to channels.