Technical description and composition of the TCL 29B340 TV, panel type and applicable modules. The composition of the modules.TCL
Model: 29B340
Chassis / Version: 40-0MS82D-MAD2LG
Panel: V290BJ1-L01
Lamp backlight: 3 LAMP CCFL
T-CON: V290BJ1-XC01
Inverter (backlight): integrated into PSU
PWM Inverter: OZ9976
Power Supply (PSU): PLC80P 81-PWL029-PW1
PWM Power: FAN7930C , OB2283B
MOSFET Power: TK12A50D
MainBoard: 40-0MS82D-MAD2LG
IC MainBoard: CPU: MST6M182VG-LF-Z1, SPI Flash: 25Q32, Audio: STA380BW
Tuner: XF-3SA 07-389SI3-NF1G
Technical Specifications L29B340
General repair guidelines for TV LCD
Possible manifestations of defects
- The TCL 29B340 TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
Most often, with such manifestations, the PLC80P main power module turns out to be faulty. It is necessary to measure its output voltages and, in case of their absence, check the serviceability of power switches (TK12A50D) and rectifier diodes in the converters for possible breakdown.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often 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. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) FAN7930C, OB2283B, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, there is a reaction to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
These manifestations can be triggered by a power supply module, or by inverter defects, as well as a distortion of the currents in the lamps due to their uneven wear. If all the electrolytic capacitors of the filter according to the inverter power supply are serviceable, you should make sure that the lamps are in good working condition, then you need to check the converter keys and the secondary windings of the transformers.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during operations, and after their completion, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the 40-0MS82D-MAD2LG 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). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - CPU: MST6M182VG-LF-Z1, SPI Flash: 25Q32, Audio: STA380BW and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board. Typically, such defects are detected by local heating of the chip.
In the absence of tuning to the channels of terrestrial or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the tuner XF-3SA
07-389SI3-NF1G. It is also necessary to check, using an oscilloscope, the presence of pulses of data exchange between the tuner and the processor via the I2C bus.
Attention to users! Self-repair of the TCL 29B340 TV without the appropriate qualifications and necessary experience can lead to its complete non-repairability!