Sunday, 12 January 2020

REPAIR / SERVICING TV SAMSUNG UE40K6550AU

Technical description and composition of the SAMSUNG UE40K6550AU TV, panel type and applicable modules. The composition of the modules.
SAMSUNG LED
Model: UE40K6550AU
Chassis / Version: FA01
Panel: CY-VK040BGLV6V
LED backlight: LM41-00235A
T-CON: BN41-02481A BN95-02675A
LED driver (backlight): integrated into PSU
PWM LED driver: SLC7015R02
Power Supply (PSU): BN44-00871A
PWM Power: FA1A50N, FA6A21N
MOSFET Power: 60R580P
MainBoard: BN41-02534B BN94-10994T
IC MainBoard: CPU: SDP1415. Hawk-MF, SPI Flash 25Q41BSIG, Sound: TAS5747
Tuner: BN40-00318A
Control: WiFi: BN59-01240A WCK720Q
Technical Specifications UE40K6550AU
SAMSUNG UE40K6550AU
General repair guidelines for TV LCD LED
Possible malfunctions
- The SAMSUNG UE40K6550AU TV does not turn on, does not respond to the remote control and the control panel buttons, does not light up or blink indicators.
In such cases, the BN44-00871A power supply is usually faulty. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches and rectifier diodes of the converters for the probability of a short circuit.
In case of breakdowns of semiconductors in secondary circuits, the converter can usually work abnormally in short circuit mode, and during short circuit in the power elements of the primary circuit, the main fuse often 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), in the absence of external damage and a short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
The most likely in these cases is a malfunction of the LED backlight. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To detect a break in the LED lines without disassembling the panel, a current source is required. It is impossible to open transitions connected in series with a simple multimeter; voltage of several tens of volts is necessary.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights up constantly or blinks.
Repair or diagnostics of the BN41-02534B 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). If it is not possible to replace the MB board (SSB), you need to check the health of its elements - CPU: SDP1415. Hawk-MF, SPI Flash 25Q41BSIG, Sound: TAS5747. Defective components should be replaced.
If there is no reception of television channels, but the TV is working properly from external devices, first of all, check the voltage of the tuner BN40-00318A and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Attention to users! Self-repair of a SAMSUNG UE40K6550AU TV without the appropriate qualifications and necessary experience can lead to its complete non-repairability!

 The appearance of the MainBoard BN41-02534B is shown in the figure below:
BN41-02534B
BN41-02534B can be used in TVs:
SAMSUNG UE40K5500 (Panel CY-KK040BGLV1V), SAMSUNG UE32K5500 UE32K5500AW (Panel CY-KK032BGAV1V), SAMSUNG UE49K5500 UE49K5500BU (Panel CY-KK049BGLV1V).
The appearance of the power supply
Main features of the SAMSUNG UE40K6550AU device:
Installed matrix (LED-panel) CY-VK040BGLV6V.
The matrix control uses the Timing Controller (T-CON) BN41-02481A.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the PLC controller SLC7015R02.
The necessary supply voltages for all nodes of the SAMSUNG UE40K6550AU TV are generated by the BN44-00871A power supply module or its analogs using FA1A50N, FA6A21N microchips and 60R580P type power switches.
MainBoard - the main board (motherboard) is a BN41-02534B module using CPU chips: SDP1415. Hawk-MF, SPI Flash 25Q41BSIG, Sound: TAS5747 and others.
The tuner BN40-00318A provides the reception of television programs and tuning to channels.