Technical description and composition of the BBK LEM1988DT TV, type of panel and applicable modules. The composition of the modules.BBK LED
Model: LEM1988DT
Chassis / Version: L0M05 (01)
Panel: V185B1-LE1 Rev. C1 CMO
LED driver (backlight): LDA15-42V160H
PWM LED driver: BIT3251
MOSFET LED driver: B6010D
Power Supply (PSU): L-CEM1 FSE040A REV: 1.3
PWM Power: LD7535 (PWM 6 pin)
MOSFET Power: SVD4N65F, HBR20100
MainBoard: L0M05 (01) (MSD309)
IC MainBoard: M-Star MSD309PX-LF-SW, APBC429D, 1135B, Spi Flash: 25Q32BVSIG
Tuner: R620D
Control: RC-LEM100
Technical Specifications LEM1988DT
BBK LEM1988DT
General repair guidelines for TV LCD LED
BBK LEM1988DT, like other televisions, it is advisable to start repairing with a careful examination of the external and internal elements and modules. Often, based on certain external signs, it may be possible to draw certain conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. If charred resistors, swollen electrolytic or cermet capacitors, ring cracks in the soldered terminals of transformers or heating elements are detected, it is advisable to establish the causes and consequences of the malfunction that has arisen, as well as to check the connected elements and assemblies.
Sometimes the BBK LEM1988DT TV simply does not turn on. No control lights on the front panel are lit or blinking, the TV does not respond to the remote control and does not make any sounds or any signs of life when turned on. The most likely cause of the malfunction is a failure of the common power module. If it is working properly, you need to check the processor batteries on the SSB (Main Board). In the general case, first of all, it is necessary to check the electrolytic capacitors of the secondary rectifier filters and the fuse at the input of the network. If it is broken, then you should check for breakdown of the PN junctions of the rectifier bridge diodes and the key transistor of the converter, which can either be on a separate radiator or integrated with a PWM controller in a common chip. Possible options.
As a rule, the keys in switching power supplies (SMPS) are reliable enough and rarely fail for no reason to be looked for by checking other components of the circuit - electrolytic capacitors, resistors and semiconductor elements of the primary circuit. The PWM chip is verified by replacing it with a known good one.
If the BBK LEM1988DT does not have an image, but there is sound, the backlight LEDs of the V185B1-LE1 Rev.C1 CMO panel or their power converter may malfunction. You should also make sure that the electrolytic capacitors of the secondary rectifiers of the common power supply are working.
To check the health of the LEDs and contact connections in their power circuit, the panel must be disassembled.
To check the LED lines for breaks without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter, a voltage of the order of several tens of volts is required.
Diagnosis and repair of the L0M05 (01) motherboard is carried out by checking the performance of the stabilizers or power converters of the module chips. In some cases, a software update is required.
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 - the B-chip M-Star MSD309PX-LF-SW APBC429D 1135B, Spi Flash - 25Q32BVSIG and replace the 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.
Owners and users of the BBK LEM1988DT TV must remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> Chassis MSD309B Schematic diagram
HOTEL service mode:
Press MENU and enter 2580 for hotel menu
Hotel Lock ON, Lock Channel OFF, Set Source ATV, Channel Number 0, Picture Lock OFF, Key Lock OFF, Max Volume 100, Source Lock, Clear Lock.
FIRMWARE FOR SPI FLASH -----------> BBK LEM1988DT, Main: L0M05 (01) (MSD309), Panel: E185SG01 rev 01
The appearance of the MainBoard L0M05 is shown in the figure below:MainBoard L0M05 uses the MSD309B processor, a BGA version of the DDRAM random access memory (RAM) and 25Q32 type SPI Flash ROM (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.
L0M05 can be used in TVs:
BBK LED1955DT (Panel V185B1-LE1 Rev.C1), BBK LED2275FDT (Panel V215H1-LE1 REV.C1), BBK LED2475FDT (Panel LC230EUE (TD)(A1)), BBK LEM1968DT Ver1 (Panel V185B1-LE1 Rev.C1), BBK LEM2488FDT (Panel LC230EUE), BBK LEM1988DT (Panel V185B1-LE1 Rev.C1 CMO), BBK LED2455FDT (Panel LC230EUE (TD)(A1)).
The appearance of the power supply
Main features of the BBK LEM1988DT device:
Installed matrix (LED-panel) V185B1-LE1 Rev.C1 CMO.
The LED driver LDA15-42V160H is used to power the backlight LEDs, it is controlled by the BIT3251 PWM controller. As power elements of the LED driver, keys of the type B6010D are used.
The necessary supply voltages for all nodes of the BBK LEM1988DT TV are generated by the L-CEM1 power module or its analogs using LD7535 microcircuits (PWM 6 pin) and power switches of the SVD4N65F, HBR20100 type.
MainBoard - the main board (motherboard) is an L0M05 module, using microchips M-Star MSD309PX-LF-SW, APBC429D, 1135B, Spi Flash: 25Q32BVSIG and others.
The R620D tuner provides TV reception and channel tuning.
Information from an alternative source:
BBK LEM1988DT
Panel Type (Matrix): V185B1-LE1 REV. C1
Motherboard: LOM05 (01) 1108H1157, MSD309PX, W25Q32, MP1484EN, YD1517P
LED Driver: LDA15-42V160H, BIT3251, B6010D
PSU: FSE040A REV: 1.3 L-CEM1 E249823 JLH94-VOC, 3S1 (SOT 23-6), SVD4N65F, HBR20100
Remote control: RC-LEM100
Additional technical information about the panel:
Brand: CMO
Model: V185B1-LE1
Type: a-Si TFT-LCD, Panel
Diagonal size: 18.5 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 409.8x230.4 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit), CIE1931 70%
Response Time: 1.3 / 3.7 (Tr / Td)
Frequency: 60Hz
Lamp Type: 13S8P WLED Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V
Brand: BBK, Model: LEM1988DT.
Briefly from the TV: LCD, 720p HD, diagonal 19 "(48 cm), HDMI: 2, USB, backlight type: Edge LED.
The composition includes MainBoard L0M05 (01) (MSD309) and LCD panel (matrix) V185B1-LE1 Rev.C1 CMO.
Power Supply Unit (PSU) L-CEM1 FSE040A REV: 1.3 Power Supply.
BBK LEM1988DT LED TV with V185B1-LE1 LCD, 19 "(48 cm) diagonal, 16: 9 format. The required screen brightness of 250 cd / m² is provided by LED backlighting. The ratio of maximum brightness to minimum (contrast) is 1000 : 1. This model uses edge LED backlighting. It is possible to view images in high quality HD at a resolution of 1366x768 pixels in the standard for graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC . Graphic processing and the formation of the digital signal is in 480i standards, 480p, 576i, 576p, 720p, 1080i, 1080p Supported multimedia file formats:. MP3, WMA, MPEG4, MKV, JPEG.
The power of the acoustic system of sound 6 W (2x3 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, audio x2, SCART, RGB, VGA, HDMI x2, 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 30 watts.
Overall dimensions: With stand 470x341x150 mm, Without stand 461x302x51 mm.
Mass of the TV: 3.3 kg.
Attention! The BBK LEM1988DT V185B1-LE1 Rev.C1 CMO panel 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.
