Sunday, 12 January 2020

REPAIR / SERVICING TV SAMSUNG UE40KU6020U

Technical description and composition of the SAMSUNG UE40KU6020U TV, panel type and applicable modules. The composition of the modules.
SAMSUNG LED
Model: UE40KU6020U UE40KU6020
Chassis / Version: BN41-02528A
Panel: CY-GK040HGLV1V
LED backlight: LM41-00239A & LM41-00240A
LED driver (backlight): integrated into PSU
MOSFET LED driver: N-FET TO-220F
Power Supply (PSU): BN41-02499A REV1.3 BN94-10711A
MOSFET Power: IPAW60R380CE
MainBoard: BN41-02528A BN94-10798B
IC MainBoard: SDP1531, K4F8E304HBMGCH, 25Q80DVSIG, 25Q40CLSIP, S24C512C
Tuner: BN40-00323A
Control: Wi-Fi: WIDT30Q BN59-01174D
Technical Specifications UE40KU6020U
SAMSUNG UE40KU6020U
General repair guidelines for TV LCD LED
Possible malfunctions
- The SAMSUNG UE40KU6020U TV does not turn on and does not show any signs of operability at all. There is no reaction to the remote control and control buttons from the front panel.
Most likely in this case, the main switching power supply (IIP) BN41-02499A is faulty. It is necessary to measure its output voltages, and in case of their absence (full or partial), you should check the serviceability of power switches (IPAW60R380CE) of converters and rectifier diodes for the presence of a possible short circuit.
In case of breakdowns of diodes in the secondary circuits, the converter can operate in emergency short circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key usually breaks.
The 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 (OOS) stabilization circuits. PWM controllers (PWM), if they do not have visible damage to the chassis and open short circuit between the terminals, are usually checked by replacement.
- There is no image, there is sound, there is a reaction to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
Failure in most such cases is detected in the nodes and backlight elements of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as an indicator of serviceability. In faulty LEDs, the zener diode will either be cut off or broken into short-circuit.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the BN41-02528A 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements SDP1531, K4F8E304HBMGCH, 25Q80DVSIG, 25Q40CLSIP, S24C512C. BGA chip malfunctions are usually easy to detect by warming up.
If you suspect a malfunction of the BN40-00323A tuner, first of all, you need to verify the correctness of the software, as well as the presence of the necessary voltage levels and pulses of data exchange with the processor via the I2C bus at the corresponding terminals of the tuner.
We recommend the owners of the UE40KU6020U TV for repair only to qualified specialists with the necessary work experience! Attempts to repair it yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!


The appearance of the MainBoard BN41-02528A is shown in the figure below:
BN41-02528A
BN41-02528A can be used in TVs:
SAMSUNG UE43KU6650U (Panel CY-VK043HGAV5V), SAMSUNG UE43KU6000W UE43KU6000 (Panel CY-GK043HGEV1H), SAMSUNG UE55KU6400 UE55KU6400U (Panel CY-KK055HQLV4H), SAMSUNG UE49KU6670 UE49KU6670U (Panel CY-VK049HGLV4V), SAMSUNG UE40KU6000U (Panel LSF400FN05-L03 CY-GK040HGLV4V) , SAMSUNG UE40KU6300U (Panel CY-WK040HGLV1V), SAMSUNG UE43KU6500U (Panel CY-VK043HGAV4V T430QVR01.0), SAMSUNG UE40KU6402U (Panel CY-KK040HGNV4H).
The appearance of the power supply
Main features of the SAMSUNG UE40KU6020U device:
Installed matrix (LED-panel) CY-GK040HGLV1V.
To power the backlight LEDs, a converter is used, combined with a power supply. As the power elements of the LED driver, keys of the N-FET TO-220F type are used.
The formation of the necessary supply voltages for all nodes of the SAMSUNG UE40KU6020U TV is carried out by the BN41-02499A power module, or its analogs using IPAW60R380CE type power switches.
MainBoard - the main board (motherboard) is a module BN41-02528A, using microchips SDP1531, K4F8E304HBMGCH, 25Q80DVSIG, 25Q40CLSIP, S24C512C and others.
The tuner BN40-00323A provides the reception of television programs and tuning to channels.