Saturday 11 April 2020

REPAIR / SERVICING TV DAEWOO L40S645VTE

Technical description and composition of the DAEWOO L40S645VTE TV, type of panel and applicable modules. The composition of the modules.
DAEWOO LED
Model: L40S645VTE
Chassis / Version: TP.MS3463S.PB783
Panel: LVF400SSDE E3 V55
LED backlight: CRH-ES40WW3030080358UREV1.1B
LED driver (backlight): integrated into PSU
PWM LED driver: MP3398A
MOSFET LED driver: ME15N10-G
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: TP.MS3463S.PB782 3MS63AX2 02-SHV63A-C0020000 024
IC MainBoard: SPI FLASH: 25Q64, AUDIO: TPA3110LD2
Tuner: XF-3SDT-H (R840)
Control: IR: 40-22D160-IRE2LG
Technical Specifications L40S645VTE
DAEWOO L40S645VTE
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The DAEWOO L40S645VTE TV does not turn on and does not show any signs of turning on, it does not respond to the control buttons or the remote control.
In such cases, the AC / DC voltage converter, which is combined with the main board TP.MS3463S.PB782, is often faulty. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, it is necessary to check the serviceability of power switches and rectifier diodes for possible breakdown (short circuit).
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more 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 SOT23-6 PWM chips are usually checked by replacing with new ones, or obviously working.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. 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 check the LED strips 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 transitions in forward bias, you can sometimes detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- 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 TP.MS3463S.PB782 motherboard should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - SPI FLASH: 25Q64, AUDIO: TPA3110LD2 and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
The malfunction of the tuner XF-3SDT-H (R840) is established after checking the software and all the 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 independently repair the DAEWOO L40S645VTE 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!
To reduce the backlight current, the total resistance of the resistors relative to the housing on the ISET pin of the MP3398A should be proportionally increased. ISET (current setting) - pin 8 in the SOIC-20 package or pin 6 in the SOIC-16 package.


The appearance of MainBoard TP.MS3463S.PB782 is shown in the figure below:
TP.MS3463S.PB782
TP.MS3463S.PB782 can be used in TVs:
DAEWOO L32S645VTE (Panel ST3151A05-8 VER.2.4), TELEFUNKEN TF-LED32S20T2 (Panel ST3151A05-8 Ver.2.5 LVW320CSDX), TELEFUNKEN TF-LED32S17T2 (Panel ST3151A05-8).
Main features of the DAEWOO L40S645VTE device:
Installed matrix (LED-panel) LVF400SSDE E3 V55.
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the MP3398A PWM controller. As power elements of the LED driver, keys of the type ME15N10-G are used.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a module TP.MS3463S.PB782, using microchips SPI FLASH: 25Q64, AUDIO: TPA3110LD2 and others.
Tuner XF-3SDT-H (R840) provides the reception of television programs and tuning to channels.

Brand: DAEWOO, Model: L40S645VTE.
Briefly from the TV: LCD, LED backlight, 40 ", 1920x1080, 1080p Full HD, DVR, sound: 16W, HDMI: 2.
The composition includes MainBoard TP.MS3463S.PB783 3MS63AX2 02-SHV63A-C0020000 024 and LCD-panel LVF400SSDE E3 V55. The power supply is combined with the MainBoard.
Technical description
DAEWOO L40S645VTE LED TV with LVF400SSDE LCD, 40 "(102 cm) diagonal, 16: 9 format. LED display technology is implemented in the model’s display technology. The design and technical capabilities of the TV include watching programs and movies in high quality HD at Resolution 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
The power of the sound speaker system 16 W (2x8 W) is provided by two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), VGA, HDMI x2, MHL, USB. A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: With stand 924x595x216 mm, Without stand 924x550x86 mm.
Attention! The LVF400SSDE E3 V55 panel of a DAEWOO L40S645VTE LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable