Saturday 11 April 2020

REPAIR / SERVICING TV DAEWOO L24S630VKE

Technical description and composition of the DAEWOO L24S630VKE TV, panel type and applicable modules. The composition of the modules.
DAEWOO LED
Model: L24S630VKE
Chassis / Version: MSD3463-T4C1
Panel: HV236WHB-H00
LED driver (backlight): integrated into MainBoard
PWM LED driver: OB3350CP
MOSFET LED driver: AOD4286
Power Supply (PSU): integrated into MainBoard
PWM Power: LNK6777
MainBoard: MSD3463-T4C1
IC MainBoard: SPI Flash: MX25L6406E, Audio: TPA3110LD2
Tuner: ST43WS-2A-E
Technical Specifications L24S630VKE
DAEWOO L24S630VKE
General repair guidelines for TV LCD LED
Possible malfunctions
- DAEWOO L24S630VKE does not turn on, does not respond to buttons and remote control, indicators on the front panel do not light up and do not blink.
The malfunction in such cases, first of all, should be sought in the power elements of a switching power supply (IIP) - a network voltage converter (AC / DC), which in this TV model is combined with the MainBoard MSD3463-T4C1 main board. It is necessary to verify the presence of its output voltages and, if they are completely absent, check the power switches and rectifier diodes for a probable short circuit.
In the event of a breakdown in the secondary circuits of the converter, it can usually fail in short circuit mode, and in case of a short circuit in the power elements of the primary circuit, the mains fuse or current sensor at the source of the key most often breaks.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers LNK6777, in the absence of visible damage or frank short-circuit between the terminals, are checked by replacing with new, or obviously working.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
In some of these cases, the malfunction is caused by a lack of backlighting on the display. The reason can sometimes be in the power of the LEDs, but more often in their malfunction (breakdown or break), sometimes in the violation of the contact connections of the LED strips.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the motherboard MSD3463-T4C1 should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - SPI Flash: MX25L6406E, Audio: TPA3110LD2 with new or obviously working ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
If you suspect a malfunction of the ST43WS-2A-E tuner, first of all, it is necessary 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.
Attention! For users and owners of L24S630VKE TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.



SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    MSD3463-T4C1 Power supply & LED-Driver

FIRMWARE FOR SPI FLASH  ----------->   DAEWOO L24S630VKE, Main: MSD3463-T4C1, Panel: K236WD8



The appearance of the MainBoard MSD3463-T4C1 is shown in the figure below:

MSD3463-T4C1

Main features of the DAEWOO L24S630VKE device:

Installed matrix (LED-panel) HV236WHB-H00.
To power the backlight LEDs, a converter is used, combined with the main board MSD3463-T4C1, controlled by the OB3350CP PWM controller. As power elements of the LED driver, keys of the AOD4286 type are used.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using LNK6777 microcircuits.
MainBoard - the main board (motherboard) is an MSD3463-T4C1 module using SPI Flash chips: MX25L6406E, Audio: TPA3110LD2 and others.
The ST43WS-2A-E tuner provides TV reception and channel tuning.
 
 Brand: DAEWOO, Model: L24S630VKE.
Shortly from the TV: LCD, LED backlight, 24 ", 1366x768, 720p HD, sound: 8W, HDMI connectors: 2.
The composition uses MainBoard MSD3463-T4C1 and LCD panel (matrix) K236WD8.
Technical description
DAEWOO L24S630VKE LED TV with K236WD8 LCD display, 24 "(61 cm) diagonal size in 16: 9 format. The required screen brightness of 240 cd / m² is provided by LED backlighting. LED display technology is implemented in the model display technology. Viewing is possible images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready).
The power of the speaker system of sound 8 W (2x4 W) provide two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, VGA, HDMI x2, MHL, USB. A digital tuner is capable of receiving television channels in the DVB-T, DVB-T2 standards.
Overall dimensions: With stand 977x624x216 mm, Without stand 550x360x66 mm.
Attention! The K236WD8 panel of a DAEWOO L24S630VKE 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.