Wednesday 16 September 2020

REPAIRING / SERVICING TV SAMSUNG UE49N5570AU

Technical description and composition of the SAMSUNG UE49N5570AU TV, panel type and modules used. The composition of the modules.
SAMSUNG LED
Model: UE49N5570AU
Chassis / Version: BA01
Panel: CY-NN049BGEV1V
LED backlight: BN61-15483A 2X38_3030C_D6T-2D1_19S2P
T-CON: 47-6021079 HV490FHB-N8A
LED driver (backlight): integrated into PSU
PWM LED driver: SO-16
MOSFET LED driver: TO-252
Power Supply (PSU): BN44-00957A L49E5_NDY
PWM Power: PFC (SO-8), PWM (SO-16)
MOSFET Power: TO-252
MainBoard: BN41-02575B BN94-13025M
IC MainBoard: CPU: SDP1604, eMMC: THGBMDG5D1LBAIT, SPI Flash: 25Q40, EEPROM: 25C512
Tuner: BN40-00331B
UE49N5570AU Specifications
SAMSUNG UE49N5570AU
General recommendations for TV LCD LED repair
Possible manifestations of defects
- SAMSUNG UE49N5570AU does not turn on, indicators on the front panel do not light or flash The TV does not respond to the control buttons and the remote control.
In such cases, the fault should be looked for first of all in the BN44-00957A power module. It is necessary to make sure that its output voltages are present and, if they are completely absent, check the power switches (TO-252) and rectifier diodes for a possible short circuit.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements, which can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying a PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) PFC (SO-8), PWM (SO-16), in the absence of external damage and short-circuit between the terminals, are checked by replacing them with known good ones.
- No picture, sound, all other TV functions are working. When turned on, the image may sometimes appear for a second.
Often, in such cases, there is no backlighting of the LED panel. 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 is also faulty.
To test the LED strips, in order 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 junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in K / Z, then the LED is faulty and needs to be replaced.
- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the BN41-02575B motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). When repairing an MB board, you need to check its components CPU: SDP1604, eMMC: THGBMDG5D1LBAIT, SPI Flash: 25Q40, EEPROM: 25C512. Defective elements must be replaced. If chips with BGA soldering technology are used, the problem in its implementation is detected by local heating of the chip.
In cases where there is no tuning for terrestrial or cable TV channels, you should make sure that the software is correct, as well as that the supply voltages on the BN40-00331B tuner terminals are in compliance. It is also necessary to check with an oscilloscope the presence of pulses of data exchange between the tuner and the processor via the I2C bus.
Remember! Attempts to self-repair the SAMSUNG UE49N5570AU 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!
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Additional MainBoard Repair
The appearance of the MainBoard BN41-02575B is shown in the figure below:
BN41-02575B
External view of the power supply
Main features of the SAMSUNG UE49N5570AU device:
Installed matrix (LED panel) CY-NN049BGEV1V.
Matrix control uses Timing Controller (T-CON) 47-6021079.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by an SO-16 PWM controller. TO-252 switches are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the SAMSUNG UE49N5570AU TV is carried out by the BN44-00957A power module, or its analogs using PFC (SO-8), PWM (SO-16) chips and power switches of the TO-252 type.
MainBoard - the main board (motherboard) is a BN41-02575B module, using CPU chips: SDP1604,eMMC: THGBMDG5D1LBAIT, SPI Flash: 25Q40, EEPROM: 25C512 and others.
Tuner BN40-00331B provides reception of television programs and tuning to channels.



SAMSUNG UE49N5570AU TV with LCD CY-NN049BGEV1V, diagonal size 48.5 "(123 cm) 16: 9 format. This model uses a panel with edge LED backlighting - Edge LED.
The CY-NN049BGEV1V sensor and the MainBoard BN41-02575B software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD). Image processing is performed using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
The UE49N5570AU TV is equipped with SMART software, built-in applications and the ability to work on the Internet. The connection to the network can be carried out via Wi-Fi wireless connection. Supported media file formats: MP3, WMA, MPEG4, DivX, MKV, JPEG.
Speaker sound system power 20 W (2x10 W) is provided by two speakers. The NICAM stereo audio processing system and the Sound Surround function are used.
Communication with other devices via an external interface is supported by standard input and output connectors: antenna input (RF), AV, component, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi, Miracast.
The digital tuner can receive TV channels in the DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2 standards.
The power consumed when operating from the mains is 128 W. Power supply BN44-00957A.
Dimensions: with stand 1105x721x297 mm, without stand 1105x644x64 mm.
TV weight: with stand: 14.6 kg, without stand: 13 kg.
Attention! Panel CY-NN049BGEV1V of LED TV SAMSUNG UE49N5570AU is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.