Technical description and composition of the DAEWOO L32V680VKE TV, panel type and modules used. The composition of the modules.
DAEWOO LED
Model: L32V680VKE
Chassis / Version: MSD3663-T5C2
Panel: LC320DXY-SLA2 // K320WDC1B
LED backlight: K320WDX A2
T-CON: 6870C-0442B
LED driver (backlight): integrated into MainBoard
PWM LED driver: OB3353CP
MOSFET LED driver: P8010BD
Power Supply (PSU): integrated into MainBoard
PWM Power: LNK6777K
MainBoard: MSD3663-T5C1 // MSD3663-T5C2
IC MainBoard: SPI FLASH: GD25Q64
Tuner: ST43WS-2A-E
Specifications L32V680VKE
DAEWOO L32V680VKE
General recommendations for TV LCD LED repair
Possible manifestations of defects
- DAEWOO L32V680VKE does not turn on, does not respond to buttons and the remote control, indicators on the front panel do not light or blink.
In this case, the main Switching Power Supply - AC / DC mains voltage converter, the elements of which are located on the MainBoard MSD3663-T5C1 main board - may be faulty. Then you should measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of the power switches and rectifier diodes of the converters for the presence of a possible short circuit.
In case of breakdowns in the secondary circuits of the converter, it can usually work in an emergency mode in a short circuit mode, and with a short circuit in the power elements of the primary circuit, the mains fuse or current sensor in the source of the key is most often cut off.
The breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM), if they do not have visible damage to the case and an outright short circuit between the terminals, are usually checked by replacing.
- No picture, sound, all other TV functions are working. When turned on, the image may sometimes appear for a second.
As a rule, in such cases there is no display backlight. Often the reason is a malfunction of the LEDs (open circuit, short circuit ...), or the connectors of the K320WDX A2 strips (strings), less often the LED driver is faulty.
It is impossible to check the line of series-connected LEDs without a special current source, and it is unsafe for them to use any voltage sources above 12V for this purpose. Then all that remains is to open the panel and check each LED separately. Usually, Chinese multimeters with 9V power supply lightly light up one 3-volt LED, if you connect the probes to it in the forward direction, the red probe to the anode, and the black one to the cathode. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or pierced in the K / Z.
If DAEWOO L32V680VKE has no picture, but there is sound, often the LC320DXY-SLA2 display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image when the external light hits the screen.
Replacing the LEDs requires disassembling the LC320DXY-SLA2 LCD panel - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels
If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But the main board MainBoard MSD3663-T5C1 often turns out to be faulty; a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to trace the passage of LVDS signals from the MainBoard MSD3663-T5C1 with an oscilloscope, as well as synchronization signals to the loops with drivers.
Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the MSD3663-T5C1 motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Complicated repair of MB (SSB) board is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the SPI FLASH: GD25Q64. BGA chip faults are usually easy to detect by warm-up.
If there is no reception of television channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the ST43WS-2A-E tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.
Attention to TV owners! Attempts to repair DAEWOO L32V680VKE by yourself are not recommended by the manufacturer and can lead to serious negative consequences!
Backlight current limitation. OB3353CP. General recommendations
To reduce the backlight current in LED drivers with OB3353CP controller, increase the resistance of the current sensor - a block of low-resistance resistors to which the cathodes of LEDs are connected. The signal from the sensor is fed to the FB input of the OB3353CP microcircuit (pin 5).
DOWNLOAD SCHEMATIC MANUAL FOR IC ------------------> OB3353A
The appearance of the MainBoard MSD3663-T5C1 is shown in the figure below:
MSD3663-T5C1
Main features of the DAEWOO L32V680VKE device:
Installed matrix (LED panel) LC320DXY-SLA2 or K320WDC1B.
Matrix control uses the Timing Controller (T-CON) 6870C-0442B.
To power the backlight LEDs, a converter combined with the MSD3663-T5C1 main board is used, controlled by the OB3353CP PWM controller. The keys of the P8010BD type are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using LNK6777K microcircuits.
MainBoard - the main board (motherboard) is an MSD3663-T5C1 module, using SPI FLASH chips: GD25Q64 and others.
The ST43WS-2A-E tuner provides reception of television programs and tuning to channels.
LED TV DAEWOO L32V680VKE with LCD display LC320DXY-SLA2, diagonal size 32 "(81 cm) 16: 9 format. The display technology of the model is implemented with LED backlighting.
The LC320DXY-SLA2 matrix and software (software) of the MainBoard MSD3663-T5C1 are capable of realizing HD image quality at a resolution of 1366x768 pixels in 720p (HD Ready). Supported media file formats: MP3, MPEG4, DivX, MKV, JPEG.
Speaker power 12 W (2x6 W) is provided by two speakers. Uses NICAM stereo processing system and Sound Surround function.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, VGA, HDMI x2, USB. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.
The power consumed by the TV operating in mains mode is 55 W. MainBoard power supply.
Dimensions: with stand 732x484x184 mm, without stand 732x432x76 mm.
TV weight: 3.9 kg.
Attention! Panel LC320DXY-SLA2 LED TV DAEWOO L32V680VKE 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.