Monday 23 March 2020

REPAIR / SERVICING TV BBK 43LEX-5009

Technical description and composition of the BBK 43LEX-5009 TV, type of panel and applicable modules. The composition of the modules.
BBK LED
Model: 43LEX-5009 / FT2C
Chassis / Version: CV628H-T42
Panel: LC430DUY (SH) (A1) // CX430DLEDM
LED backlight: 180.DT0-431900-0H HL-00430A28-1201S-01
T-CON: 6870C-0532A + 6870S-1932C 6870S-1933C
LED driver (backlight): integrated into MainBoard
PWM LED driver: BIT3267
MOSFET LED driver: AOD4454
Power Supply (PSU): integrated into MainBoard
PWM Power: LD7536 (PWM SOT23-6)
MOSFET Power: SMK10N60
MainBoard: CV628H-T42
IC MainBoard: 25Q16, KLM4G1FEPD, TPA3110D2
Control: RC-LEX500
Technical Specifications 49LEX-5048 / FT2C
BBK 43LEX-5009
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The BBK 43LEX-5009 TV does not turn on and does not show any signs of operability at all. There is no reaction to either the remote control or the front panel control buttons.
In such cases, the common power source, the AC / DC voltage converter, which is combined with the elements of the CV628H-T42 main board, is often faulty. It is then necessary to measure its output voltages in the secondary circuits, and if they are absent, check the operability of the power switches of the converters and rectifier diodes for the possible breakdown of semiconductors (CI).
In case of any breakdowns of power elements in the secondary circuits of the 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 mains fuse and, less often, the current sensor at the source of the key are most often cut off.
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 reacts to the remote control. Or the image appears when you turn it on and immediately disappears
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.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source. By opening the panel, each LED can be checked separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect probes in the forward direction to it. 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 indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the CV628H-T42 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). In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its chips 25Q16, KLM4G1FEPD, TPA3110D2 and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.

It should be remembered! Attempts to independently repair the BBK 43LEX-5009 TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!


psu led  / SERVICE MANUAL   ------------------>    CV628H-T42 Power supply
 The appearance of the MainBoard CV628H-T42 is shown in the figure below:
CV628H-T42
CV628H-T42 can be used in TVs:
BBK 43LEX-5009/FT2C (Panel LC430DUY (SH)(A1)), BBK 40LEX-5025/FT2C (Panel V400HJ6-PE1 DLEDSV400FHD), BBK 32LEX-5027/T2C (Panel V320BJ6-Q01 Rev.C1), SUPRA STV-LC40ST900FL (Panel V400HJ6-PE1).
Main features of the BBK 43LEX-5009 device:
Installed matrix (LED-panel) LC430DUY (SH) (A1) or CX430DLEDM.
The matrix control uses the Timing Controller (T-CON) 6870C-0532A.
To power the backlight LEDs, a converter is used, combined with the main board CV628H-T42, controlled by a BIT3267 PWM controller. As power elements of the LED driver, keys of the AOD4454 type are used.
The power module is combined with the MainBoard and is designed according to the flyback AC / DC voltage converter using LD7536 microcircuits (PWM SOT23-6) and power switches of the SMK10N60 type.
MainBoard - the main board (motherboard) is a CV628H-T42 module, using 25Q16, KLM4G1FEPD, TPA3110D2 and other chips.