Monday 23 March 2020

REPAIR / SERVICING TV BBK 40LEM-3080

Technical description and composition of the BBK 40LEM-3080 TV, type of panel and applicable modules. The composition of the modules.
BBK LED
Model: 40LEM-3080 / FT2C
Chassis / Version: 920E3PU
Panel: ECG390AH-LD2 (SN) // ECG390AH-LD1 (SN)
LED backlight: CHA 39 3228 05 REV1.2
T-CON: 39T01-C03 T390HVN01.0 + 39T01-S04
LED driver (backlight): integrated into PSU
Power Supply (PSU): MP100D-1MF12 Rev1.0
PWM Power: OB2273, LD7531 (PWM SOT23-6), UCC28019A (8)
MainBoard: JUC7.820.00084054 LS1B 32C2000
IC MainBoard: 25Q64BSIG
Tuner: DMI21-C2I3RH
Control: RC-LEM100, RC-LEM2012
Technical Specifications 49LEX-5048 / FT2C
BBK 40LEM-3080
General repair guidelines for TV LCD LED
Possible malfunctions
- BBK 40LEM-3080 does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
Often in such cases, the MP100D-1MF12 power module 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 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 OB2273, LD7531 (PWM SOT23-6), UCC28019A (8) can also cause a malfunction of the power switch of the converter and is checked by replacement.
- 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 of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts is required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as a health indicator. In faulty LEDs, the zener diode will either be cut off or broken into short-circuit.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the JUC7.820.00084054 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). Board repair and replacement of 25Q64BSIG microcircuits are carried out with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
Before replacing the DMI21-C2I3RH tuner, if there is no tuning for the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Attention! For users and owners of 40LEM-3080 TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.


FIRMWARE FOR SPI FLASH  ----------->   BBK 40LEM-3080FT2C, Main: JUC7.820.00084054 LS1B 32C2000, Panel: ECG390AH-LD1 (SN)

 The appearance of the MainBoard LS1B is shown in the figure below:
LS1B
JUC7.820.00084054 can be used in TVs:
BBK 40LEM-3080/FT2C (Panel ECG390AH-LD2 (SN)), BBK 32LEM-3081/T2C (Panel M320X13-E2-H), BBK 32LEM-1003/T2C (Panel M320X13-E4-L HD), DEXP 28A3000 (Panel R-HS055D-1MF), DEXP 50A7000 (Panel C500F13-E3-A), DNS C28DC2000 (Panel M280X13-E1-H), DNS C39DC2000 (Panel M390F13-E1-A), ERISSON 42LEC2000 (Panel M420F13-E1-L (G1)), ERISSON 55LEC2000 (Panel M550F13-E1-A 1080p Full HD), ERISSON 28LEC2000 (Panel M280X13-E1-H), RUBIN RB-32SD8T2C (Panel M320X13-E3-H), TELEFUNKEN TF-LED32S12T2 (Panel M320X12-E9-A(1)).
The appearance of the power supply
Main features of the BBK 40LEM-3080 device:
Installed matrix (LED-panel) ECG390AH-LD2 (SN) or ECG390AH-LD1 (SN).
The matrix control uses the Timing Controller (T-CON) 39T01-C03.
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 40LEM-3080 are generated by the MP100D-1MF12 power supply module or its analogs using OB2273, LD7531 (PWM SOT23-6), UCC28019A microcircuits (8).
MainBoard - the main board (motherboard) is a JUC7.820.00084054 module, using 25Q64BSIG chips and others.
The DMI21-C2I3RH tuner provides television reception and channel tuning.