Thursday 19 March 2020

REPAIR / SERVICING TV BBK LD2212K

Technical description and composition of the BBK LD2212K TV, panel type and applicable modules. The composition of the modules.
BBK
Model: LD2212K
Chassis / Version: J2252M1L.C
Panel: M216H1-L01 Rev C1
Inverter (backlight): LK-IN220417A ROHS
PWM Inverter: OB3302CP
MOSFET Inverter: AO4946
Trans Inverter: LKT-035 MD1019
Power Supply (PSU): TOPOW TP006 Rev1.0 TPC060 REV1.0
MainBoard: L2M25 (05) (TSUMV26KE-LF)
IC MainBoard: TSUMV26KE-LF, TDA7266, EN25F40, TDA1517P
Tuner: DWE-7053BW-PLL1
Control: LT121K 2229140400001
Technical Specifications LD2212K
BBK LD2212K
General recommendations for repairing TV LCD
Possible malfunctions
- The BBK LD2212K TV does not turn on and does not show any sign of turning on at all. There are no reactions to the control buttons or the remote control.
In such cases, the TOPOW power supply is usually faulty. It is necessary to measure the output voltages in the secondary circuits, 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 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. The PWM chip 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, it responds to the remote. Or the image appears when you turn it on and immediately disappears
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the L2M25 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). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard board - TSUMV26KE-LF, TDA7266, EN25F40, TDA1517P. In cases where the BGA processor is used, its malfunction is usually detected by local heating.
In the absence of 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 voltages at the terminals of the tuner DWE-7053BW-PLL1. 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.
Once again, remind users! Attempts to self-repair a BBK LD2212K TV without the appropriate qualifications and necessary experience can lead to its complete non-repairability!


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    BBK LD1912K, LD2012K Service manual and schematic

SCHEMATIC DIAGRAM  / PSU   ------------------>    LK-IN220417A



 Service Manual with Schematic Diagram 44 pages 2009-2010  the LD1912K, LD2212K.

 The appearance of the MainBoard L2M25 is shown in the figure below:
L2M25
Main features of the BBK LD2212K device:
Installed matrix (LCD panel) M216H1-L01 Rev C1.
To power the backlight, an inverter LK-IN220417A is used, it is controlled by the PWM controller OB3302CP. A transformer LKT-035 MD1019 is installed in the inverter converter. As power elements of the inverter, keys of the type AO4946 are used.
The necessary supply voltages for all nodes of the BBK LD2212K TV are generated by the TOPOW power supply module or its analogs.
MainBoard - the main board (motherboard) is an L2M25 module using TSUMV26KE-LF, TDA7266, EN25F40, TDA1517P, and others.
The tuner DWE-7053BW-PLL1 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CMO
Model: M216H1-L01
Type: a-Si TFT-LCD, Panel
Diagonal size: 21.6 inch
Resolution: 1920x1080, FHD
Display Mode: TN, Normally White, Transmissive
Active Area: 477.504x268.596 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC)
Response Time: 1.3 / 3.7 (Tr / Td)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V

 BBK LD2212K LCD TV with M216H1-L01 LCD, 22 "(55 cm) diagonal display in 16: 9 format. 400 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. Maximum brightness to minimum ratio (contrast) ) is 1000: 1. 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 digital signal generation occurs in standard max 480i, 480p, 576i, 576p, 720p, 1080i Supported media file formats: WMA, MPEG4, VideoCD, SVCD, Picture CD, JPEG.
The power of the speaker system of sound 5 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), component, SCART, RGB, VGA, HDMI, 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.
The power consumed by the TV in the operating mode from the network is 55 watts.
Overall dimensions: With stand 575x473x177 mm, Without stand 498x371x83 mm.
TV Weight: 6.8 kg.
Attention! The M216H1-L01 Rev C1 panel of the BBK LD2212K LCD TV is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!