Technical description and composition of the BBK LEM3242DT TV, type of panel and applicable modules. The composition of the modules.BBK LED
Model: LEM3242DT
Panel: LC320EXN SDA1
LED backlight: 3660L-0386A; 2 * 48 led
LED driver (backlight): PPW-LE32GD-O 6917L-0072A
PWM LED driver: BD9262EFV
MOSFET LED driver: DB31AB
Power Supply (PSU): AY068D-4SF04 Rev1.0 AY1219A18616
MainBoard: T.MSD309.9B
IC MainBoard: W9751G6JB-25 X2, 25Q32S, AIC2857F, R2A15122
Tuner: XDTT-6F1C / T1146
Technical Specifications LEM3242DT
BBK LEM3242DT
General repair guidelines for TV LCD LED
Possible malfunctions
- The BBK LEM3242DT TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
Most often, with such manifestations, the main power module AY068D-4SF04 is found to be faulty. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary first of all to check the power switches and rectifier diodes for a possible partial or complete breakdown.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch may be PWM (PWM). It is checked only by replacement with a known good one.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
Often in such cases, there is no LED backlight. The reason can be both in the power of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source. By opening the panel, each LED can be checked separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect probes in the forward direction to it. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the T.MSD309.9B 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). 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 - W9751G6JB-25 X2, 25Q32S, AIC2857F, R2A15122 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.
Before replacing the XDTT-6F1C / T1146 tuner, if there is no tuning for the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via I2C
Attention! Users and owners of LEM3242DT TVs who do not have the appropriate qualifications, knowledge and experience are strongly advised against self-repair attempts in order to avoid negative consequences that could lead to complete non-repairability of the device.
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> Chassis MSD309B Schematic diagram
To reduce the backlight current in LED drivers with the BD9262EFV controller, the total resistance of the resistors from terminal 23 (ISET) to the housing should be proportionally increased.Repair MainBoard
The appearance of MainBoard T.MSD309.9B is shown in the figure below:
T.MSD309.9B
MainBoard T.MSD309.9B uses the MSD309B processor, DDRAM random access memory (RAM) in BGA version and SPI Flash ROM type 25Q32 (4Mb).
It is advisable to start the repair of the motherboard by checking the voltage converters and linear stabilizers necessary to provide power to the nodes in the operating and standby modes. The processor core is powered by + 1.5V. Also, the processor voltage requires + 2.5V and + 3.3V.
If the display backlight is OK and there is no image, it is necessary to check the panel power (depending on the type, + 5V or + 12V), which is more convenient to measure directly on the LVDS connector. If, in the presence of all the supply voltages, the TV does not enter the operating mode, does not respond to the Remote Control and control buttons, you should update the SPI Flash firmware.
T.MSD309.9B can be used in TVs:
BBK LEM3242DT (Panel LC320EXN SDA1), BBK LEM3241FDT (Panel 32 дюйма), BBK LEM2687FDT (Panel V260H1-LE1), IZUMI TLE32D400B (Panel V315H3-LE4), SUPRA STV-LC3245LF (Panel TC-315F1H2), SUPRA STV-LC39T820FL (Panel TC390FP01-B), SUPRA STV-LC46T810FL (Panel 1080p Full HD 1920x1080), SUPRA STV-LC39T810FL (Panel TC390FP01-A).
Main features of the BBK LEM3242DT device:
Installed matrix (LED-panel) LC320EXN SDA1.
The LED driver PPW-LE32GD-O is used to power the backlight LEDs, it is controlled by the BD9262EFV PWM controller. As power elements of the LED driver, keys of the DB31AB type are used.
The formation of the necessary supply voltages for all nodes of the BBK LEM3242DT TV is carried out by the power module AY068D-4SF04, or its analogues.
MainBoard - the main board (motherboard) is a module T.MSD309.9B, using microcircuits W9751G6JB-25 X2, 25Q32S, AIC2857F, R2A15122 and others.
The tuner XDTT-6F1C / T1146 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC320EXN-SDA1
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare (Haze 10%), Hard coating (3H)
Brightness: 380 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
BBK LEM3242DT LED TV with LC320EXN LCD, 32 "(81 cm) diagonal size in 16: 9 format. The required screen brightness of 380 cd / m² is provided by LED backlighting. The ratio of maximum brightness to minimum (contrast) is 1200: 1 This model uses side illumination from Edge LEDs. You can view images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. GraphicDigital signal processing and generation takes place in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, DivX, MKV, JPEG.
The power of the sound system 16 W (2x8 W) provides 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, audio x2, component, SCART, RGB, VGA, HDMI x3, USB. An output for connecting headphones is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768, 1360x768. The digital tuner is capable of receiving television channels in DVB-T MPEG4 standards.
The power consumed by the TV in the operating mode from the network is 80 watts.
Overall dimensions: With stand 780x546x205 mm, Without stand 780x491x46 mm.
Mass of the TV: 8.15 kg.
Attention! The LC320EXN SDA1 panel of the BBK LEM3242DT 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.
