Monday 23 March 2020

REPAIR / SERVICING TV BBK 49LEM-1041

Technical description and composition of the TV BBK 49LEM-1041, type of panel and applicable modules. The composition of the modules.
BBK LED
Model: 49LEM-1041 FT2C
Chassis / Version: CV512H-A20
Panel: HV490QUB
T-CON: HZ-ME36-BOE49
LED driver (backlight): integrated into PSU
Power Supply (PSU): LK-PL460203B
MainBoard: CV512H-A 20
IC MainBoard: SPI FLASH: GD25Q64
Tuner: NoName
Technical Specifications 49LEM-1041 / FTS2C
BBK 49LEM-1041
General repair guidelines for TV LCD LED
Possible malfunctions
- The BBK 49LEM-1041 TV does not turn on and does not show any signs of turning on, it does not respond to the control buttons or to the remote control.
In some of these cases, the main switching power supply, the LK-PL460203B module, is faulty. It is then necessary to measure its output voltages and, if they are absent, it is necessary to check the power switches and rectifier diodes of the converters for a short-circuit probability.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short-circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the main fuse and, less often, the current sensor at the source of the key most often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM microcircuits are usually checked by replacement with new ones, or obviously working.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
Often in such cases, there is no LED backlight. The reason can be both in the power supply 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 health in the LED circuit it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the CV512H-A 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).
Before changing the tuner SPI FLASH: GD25Q64, if there is no possibility of tuning to television channels, you should make sure that there are supply voltages that must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.


FIRMWARE FOR SPI FLASH  ----------->   BBK 49LEM-1041 FT2C, Main: CV512H-A 20, Panel: HV490QUB


 The appearance of the MainBoard CV512H-A is shown in the figure below:
CV512H-A
Main features of the BBK 49LEM-1041 device:
Installed matrix (LED-panel) HV490QUB.
The matrix control uses the Timing Controller (T-CON) HZ-ME36-BOE49.
To power the backlight LEDs, a converter is used, combined with a power supply.
The necessary supply voltages for all nodes of the TV BBK 49LEM-1041 are generated by the power module LK-PL460203B, or its analogs.
MainBoard - the main board (motherboard) is a CV512H-A module, using SPI FLASH chips: GD25Q64 and others.
The NoName tuner provides television reception and channel tuning.

 Brand: BBK, Model: 49LEM-1041 / FTS2C.
Briefly from the TV: LCD, LED backlight, 49 ", 1920x1080, 1080p Full HD, DVR, sound: 16W, HDMI connectors: 3.
The composition uses MainBoard CV512H-A 20 and LCD-panel HV490QUB.
Power Supply Unit (PSU) LK-PL460203B power Supply.
BBK 49LEM-1041 / FTS2C LED TV with HV490QUB LCD display, 49 "(124 cm) diagonal size of 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 1200: 1. The LED display is implemented in the model’s display manufacturing technology.The design and technical capabilities of the TV provide for viewing broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). The video or video signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: WMA, MPEG4, MKV, JPEG.
The power of the sound system 16 W (2x8 W) provide two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, SCART, 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 the standards DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2.
Overall dimensions: with stand 1098x683x224 mm, without stand 1098x633x69 mm.
The mass of the TV: 11.2 kg.
Attention! The BBK 49LEM-1041 / FTS2C LED TV panel HV490QUB 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.