Tuesday 24 March 2020

REPAIR / SERVICING TV BBK LED2475F

Technical description and composition of the BBK LED2475F TV, type of panel and applicable modules. The composition of the modules.
BBK LED
Model: LED2475F
Panel: LC230EUE TDA1
LED driver (backlight): LDA15-63V240K
MOSFET LED driver: 12N10L
Power Supply (PSU): FSE060A 1
PWM Power: LD7535 (PWM 6 pin)
MainBoard: 88XR-TL2M392475F KB-6160
Control: RC1975
Technical Specifications LED2475FDT
BBK LED2475F
General repair guidelines for TV LCD LED
Possible malfunctions
- BBK LED2475F does not turn on at all and does not show any signs of operability. Does not blink indicators and does not respond to control buttons.
Most likely in this case, the main switching power supply (IIP) FSE060A is faulty. It is necessary to measure the secondary output supply voltages, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM chip LD7535 (PWM 6 pin) can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
The most likely in these cases is a malfunction of the 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.
To check the LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, sometimes you can detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the 88XR-TL2M392475F 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).
Attention! Users and owners of LED2475F 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   ------------------>   BBK LED1975, LED2275F, LED2475F, LEM1988, LEM2288F, LEM2488F (MST6M182VG + 2IN1 POWER SUPPLY)









Main features of the BBK LED2475F device:
Installed matrix (LED panel) LC230EUE TDA1.
The LED driver LDA15-63V240K is used to power the backlight LEDs. As power elements of the LED driver, keys of the 12N10L type are used.
The necessary supply voltages are generated for all nodes of the BBK LED2475F TV by the FSE060A power module, or its analogs using LD7535 microcircuits (PWM 6 pin).
MainBoard - the main board (motherboard) is a 88XR-TL2M392475F module.
Additional technical information about the panel:
Brand: LG Display
Model: LC230EUE-TDA1
Type: a-Si TFT-LCD, Panel
Diagonal size: 23.0 inch
Resolution: 1920x1080, FHD
Display Mode: TN, Normally White, Transmissive
Active Area: 509.184x286.416 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit)
Response Time: 1.3 / 3.7 (Tr / Td)
Frequency: 60Hz
Lamp Type: 2 strings WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V


Brand: BBK, Model: LED2475FDT.
Briefly from the TV: LCD, 1080p Full HD, diagonal 24 "(61 cm), HDMI: 2, USB, backlight type: Edge LED.
The composition uses MainBoard L0M05 (01) and LCD panel (matrix) LC230EUE (TD) (A1).
Power Supply Unit (PSU) FSE060E0 F782003311 Power Supply.
BBK LED2475FDT LED TV with LC230EUE LCD, 24 "(61 cm) diagonal size in 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 side illumination from Edge LEDs.The design and technical capabilities of the TV include watching programs and movies in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). Input high-frequency or video signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, MKV, VideoCD, SVCD, Picture CD, 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, 1920x1080. 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 40 watts.
Overall dimensions: 589x491x150 mm.
The mass of the TV: 4.4 kg.
Attention! The BB2 LED2475FDT LCD TV panel LC230EUE (TD) (A1) 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.