Technical description and composition of the BBK LEM2495F TV, panel type and applicable modules. The composition of the modules.BBK LED
Model: LEM2495F
Chassis / Version: EV59XUS-Y1-A0
Panel: M230HGE-L20-C1
LED backlight: 44-D071918
LED driver (backlight): integrated into MainBoard
PWM LED driver: SOIC8
MOSFET LED driver: TO-252
Power Supply (PSU): integrated into MainBoard
MainBoard: EV59XUS-Y1-A0
IC MainBoard: CPU: TSUMV29 / 39/59, SPI Flash W25Q32,
Tuner: NoName
Technical Specifications LEM2495F
BBK LEM2495F
General repair guidelines for TV LCD LED
Possible malfunctions
- The BBK LEM2495F TV does not turn on, does not respond to the remote control and buttons on the control panel, does not light or blink indicators.
First of all, in such cases, you should verify the operability of the common switching power supply (IIP) - AC / DC voltage converter of the mains voltage. All source elements in this TV model are located on the MainBoard EV59XUS-Y1-A0 main board. 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 breakdowns of semiconductors in the secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse 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, in the absence of visible damage or explicit short-circuit between the terminals, are checked by replacing with new ones, or obviously working.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. 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 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 TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EV59XUS-Y1-A0 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the CPU elements: TSUMV29 / 39/59, SPI Flash W25Q32 ,. BGA chip malfunctions are usually easy to detect by warming up.
In cases where there is no tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the NoName tuner. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
TV users and owners need to remember that attempts to self-repair a BBK LEM2495F TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
FIRMWARE FOR SPI FLASH -----------> BBK LEM2495F, Main: EV59XUS-Y1-A0, Panel: M230HGE-L20-C1
Service Manual with Schematic Diagram 32 pages on the model -----------> LEM1993, LED1994, LEM1995, LEM1996, LEM1997, LEM2293F, LED2294F, LEM2295F, LEM2296F, LEM2297F, LEM2493F, LED2494F, LEM2495F, LEM2496F, LEM2497F, LEM2993, LED2994, LEM2995, LEM2996, LEM2997, LED2253FW, LED1952DTG, LED2252FDTG, LED2452FDTG, LED2278F
The appearance of the MainBoard EV59XUS-Y1-A0 is shown in the figure below:EV59XUS-Y1-A0
Main features of the BBK LEM2495F device:
Installed matrix (LED-panel) M230HGE-L20-C1.
To power the backlight LEDs, a converter is used, combined with the main board EV59XUS-Y1-A0, controlled by the SOIC8 PWM controller. As power elements of the LED driver, keys of the TO-252 type are used.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit.
MainBoard - the main board (motherboard) is an EV59XUS-Y1-A0 module, using CPU chips: TSUMV29 / 39/59, SPI Flash W25Q32, and others.
The NoName tuner provides television reception and channel tuning.
BBK LEM2495F LED TV with M230HGE-L20-C1 LCD display, 24 "(61 cm) diagonal size in 16: 9 format. The required screen brightness of 250 cd / m² is provided by LED backlight LED. The ratio of maximum brightness to minimum (contrast) is 1000: 1. This model uses lateral illumination from Edge LEDs. The design and technical capabilities of the TV include viewing programs and movies in high quality HD at a resolution of 1920x1080 pixels in the graphic resolution of the standard 1080p (Full HD). Input high-frequency or video signal Al can be processed in analogue systems PAL, SECAM. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG. Stereo audio is implemented in two built-in speakers using NICAM STEREO audio processing system.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, 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, 1280x1024, 1360x768.
Dimensions: With stand 547x364x130 mm, Without stand 547x336x49 mm.
Attention! The M230HGE-L20-C1 panel of the BBK LEM2495F 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.
