Tuesday 24 March 2020

REPAIR / SERVICING TV BBK LEM2249HD

Technical description and composition of the BBK LEM2249HD TV, panel type and applicable modules. The composition of the modules.
BBK LED
Model: LEM2249HD Ver1
Chassis / Version: MSTV3208-ZC01-01
Panel: CLAA215FA06
LED driver (backlight): TV2414-ZC02-01 (A)
PWM LED driver: MP3389EF
MOSFET LED driver: AO 4435 (8)
Power Supply (PSU): adapter AD-LEM1949 12v 3a
MainBoard: MSTV3208-ZC01-01
IC MainBoard: CPU: MST6M48RHS-LF-Z1; SPI Flash: 25Q32; Sound: TDA1517P
Tuner: F21WT-3BAR-E
BBK LED
Model: LEM2249HD Ver2
Chassis / Version: MSTV2407
Panel: LM215DT5D
LED driver (backlight): TV2415-ZC02-01 (A)
Power Supply (PSU): integrated into MainBoard
PWM Power: OB2273 (PWM SOT23-6)
MainBoard: MSTV2407-ZC01-01
IC MainBoard: CPU: MST6E182VG-LF, SPI Flash: EN25Q32, Audio: TPA3113D2
Tuner: F35WT-2A-E
Control: RC-LEM101
Technical Specifications LEM2249HD
BBK LEM2249HD
General repair guidelines for TV LCD LED
Possible malfunctions
- The BBK LEM2249HD TV does not turn on. There are no signs of operability. The indicators on the front panel do not shine and do not blink, and the remote control and control buttons do not respond.
Often in such cases, the main power source - the AC / DC voltage converter, which is combined with the MainBoard MSTV2407-ZC01-01 board, is faulty. It is necessary to measure its secondary output 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 short circuit in the elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch may be PWM (PWM) OB2273 (PWM SOT23-6). It is checked only by replacement with a known good one.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
Often in such cases, there is no LED backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
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 MSTV2407-ZC01-01 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 elements Cpu: MST6E182VG-LF, SPI Flash: EN25Q32. BGA chip malfunctions are usually easy to detect by warming up.
If the TV works normally from external devices, but does not tune into television channels, the tuner F35WT-2A-E may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
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.


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>   Main Board MSTV2407-ZC01-01   Applies to TVs: BBK LEM2681F, BBK LEM2682, BBK LEM2284F ............
 Service Manual with Schematic Diagram 39 pages 2012 on LED1975, LED2275F, LED2475F, LEM1988, LEM2288F, LEM2488F, LEM2681F, LEM3281F, LEM2249HD, LEM2449HD, LEM2648SD, LEM3282

 The appearance of the MainBoard MSTV2407-ZC01-01 is shown in the figure below:
MSTV2407-ZC01-01
MSTV2407-ZC01-01 motherboard is combined with a power module. The processor is MST6E182VG, or MST6E181VG, made using BGA technology. Repair of the power module is carried out according to conventional technology, starting with checking its power elements. The following is a functional check of the converters for the processor power: + 1.3V, + 1.8V, 3.3V, based on the SY8008B PWM controllers. The power supply of the built-in DDR 2.5V is generated from a 3.3V source using the P-N junction of the 1N4001 diode (3.3V-0.8V = 2.5V). Standby mode is organized from the linear stabilizer series 1117-3V3. The LCD panel is powered by either 5V or 12V, depending on the type of panel used.
MSTV2407-ZC01-01 can be used in TVs:
BBK LEM2249HD Ver2 (Panel LM215DT5D), BBK LEM2284F (Panel M215HG-LE4 Rev.C3), BBK LEM2681F (Panel V260H1-LE10 Rev. C1 ), BBK LEM2682 LEM2682DT (Panel V260B2-LE11 Rev.C1), BBK LEM3284F (Panel HV320WXC-200), Haier LE32T1000 (Panel T320XVN09.0), MYSTERY MTV-2224LW (Panel M215HG-LE4 Rev.C3), MYSTERY MTV-3222LW (Panel T320XVN01.0), MYSTERY MTV-1924LW (Panel V185B1-L17), MYSTERY MTV-3018LW (Panel V290BJ1-PE1), MYSTERY MTV-1911LW (Panel HT185WX7-100), MYSTERY MTV-1922LW (Panel V185B1-L17), MYSTERY MTV-1913LW (Panel HT185WX7-100), MYSTERY MTV-3218LW (Panel HV320WX2-20A), MYSTERY MTV-1918LW (Panel V185B1-L17), MYSTERY MTV-2213LW (Panel M215HGE-L10), MYSTERY MTV-2222LW (Panel M215HG-LE4 REV.C3), MYSTERY MTV-2418LW (Panel HM236WUA-100), MYSTERY MTV-2424LW (Panel HM236WU8-100), MYSTERY MTV-1914LW (Panel V185B1-L15 Rev.c1), MYSTERY MTV-3223LW (Panel LK315T3HB94), MYSTERY MTV-2422LW (Panel HM236WU8–100), MYSTERY MTV-3224LW (Panel T320XVN09.0), MYSTERY MTV-2218LW (Panel CLAA215FA10), MYSTERY MTV-1911WL (Panel V185B1-L15 REV.C1), MYSTERY MTV-3221LW (Panel HV320WX2-268), MYSTERY MTV-2211W (Panel M215HG-LE4 ).
Main features of the BBK LEM2249HD device:
Installed matrix (LED panel) LM215DT5D.
The LED driver TV2415-ZC02-01 (A) is used to power the backlight LEDs.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using OB2273 microcircuits (PWM SOT23-6).
MainBoard - the main board (motherboard) is an MSTV2407-ZC01-01 module, using Cpu microcircuits: MST6E182VG-LF, SPI Flash: EN25Q32, Audio: TPA3113D2 and others.
The F35WT-2A-E tuner provides television reception and channel tuning.

BBK LEM2249HD LED TV with LM215DT5D LCD display, diagonal size 22 "(56 cm) 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 The LED display technology is implemented in the model’s display manufacturing technology.The design and technical capabilities of the TV include watching programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphic resolution according to the standard 1080p (Full HD). and the 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, 1080p. Supported media file formats: MP3, WMA, MKV, JPEG. The stereo sound is realized by two built-in speakers using the 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, component, SCART, RGB, VGA, HDMI x2, USB. 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.
Overall dimensions: With stand 528x390x98 mm, Without stand 580x402x79 mm.
Mass of the TV: 3.2 kg.
Attention! The LM215DT5D panel of the BBK LEM2249HD 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.