Wednesday 25 March 2020

REPAIR / SERVICING TV BBK LEM2284F

Technical description and composition of the BBK LEM2284F TV, panel type and applicable modules. The composition of the modules.
BBK LED
Model: LEM2284F
Chassis / Version: V1.0 228-120927002
Panel: M215HG-LE4 Rev. C3
LED driver (backlight): integrated into MainBoard
PWM LED driver: AP3039AM, AP3608E
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, RT8296AH (8), PT2308 (8)
Tuner: F35WT-2A-E
Technical Specifications LEM2284F
BBK LEM2284F
General repair guidelines for TV LCD LED
Possible malfunctions
- The BBK LEM2284F TV does not turn on, does not respond to the remote control and control panel buttons, indicators do not light up and do not blink.
The malfunction in such cases, first of all, should be sought in the power elements of a switching power supply (IIP) - a network voltage converter (AC / DC), which in this TV model is combined with the MainBoard MSTV2407-ZC01-01 main board. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary first of all to check the power switches and rectifier diodes for a possible partial or complete breakdown.
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.
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 is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
In most cases, the malfunction is caused by the lack of a backlight display. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, black to the cathode). In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- 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 microcircuit and matrix. If necessary, update or replace the software (software). If it is not possible to replace the MB (SSB) card, you need to check the health of its elements - AB2LA (5), RT8296AH (8), PT2308 (8). Defective components should be replaced.
If you suspect a malfunction of the F35WT-2A-E tuner, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary voltage levels and impulses of data exchange with the processor via the I2C bus at the corresponding terminals of the tuner.
TV users and owners need to remember that attempts to self-repair a BBK LEM2284F TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>   MSTV2407-ZC01-01

 BBK LEM2681F, BBK LEM2682, BBK LEM2284F... MYSTERY MTV-3018LW, MYSTERY MTV-2211LW V9M01, MYSTERY MTV-2224LW... Haier: LE32E1600, LE32H320D, LE32B50.


FIRMWARE FOR SPI FLASH  ----------->   BBK LEM2284F, Main: MSTV2407-ZC01-01

 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 LEM2284F device:
Installed matrix (LED-panel) M215HG-LE4 Rev. C3.
To power the backlight LEDs, a converter is used, combined with the main board MSTV2407-ZC01-01, controlled by the AP3039AM, AP3608E PWM controller.
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, RT8296AH (8), PT2308 (8) and others.
The F35WT-2A-E tuner provides television reception and channel tuning.