Technical description and composition of the TCL LED40D2900S TV, type of panel and applicable modules. The composition of the modules.TCL LED
Model: LED40D2900S LED40D2900
Chassis / Version: TP.S512.PB775
Panel: LSC400HN02-802
LED driver (backlight): integrated into MainBoard
PWM LED driver: GB98AERN
MOSFET LED driver: TO-252
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MOSFET Power: TO-220
MainBoard: TP.S512.PB775
IC MainBoard: CPU: 9206B, SPI Flash: GD25Q64, TPA3110LD2
Tuner: DVB + SAT
Technical Specifications LED40D2900S
TCL LED40D2900S
General repair guidelines for TV LCD LED
Possible manifestations of defects
- TCL LED40D2900S 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.
The malfunction in such cases should be sought in the elements of the power source - the network voltage converter (AC / DC), which is located on the MainBoard TP.S512.PB775 main board. It is necessary to measure its output supply voltages, and in case of their absence, check the serviceability of power switches (TO-220) of converters and rectifier diodes for the probability of breakdown in PN semiconductor junctions.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM SOT23-6 PWM chips are usually checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
In such cases, the most likely malfunction of the LED backlight elements. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To detect a break in the LED lines without disassembling the panel, a current source is required. It is impossible to open transitions connected in series with a simple multimeter; voltage of several tens of volts is necessary.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the TP.S512.PB775 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). When repairing an MB board, you need to check its CPU components: 9206B, SPI Flash: GD25Q64, TPA3110LD2. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
Before replacing the DVB + SAT tuner, if there is no tuning to 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
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.
FIRMWARE FOR SPI FLASH ---------------------> TCL LED40D2900S LED40D2900, Main: TP.S512.PB775, Panel: LSC400HN02-802
You can reduce the backlight current in LED drivers with the GB98AERN controller by proportionally increasing the total resistance of the resistors from pin 6 (ISET) to the chassis.
The appearance of MainBoard TP.S512.PB775 is shown in the figure below:
TP.S512.PB775
TP.S512.PB775 can be used in TVs:
TCL LED40D2900 (Panel LVF400SSOT), TCL LED32D2900 LED32D2900S (Panel ST3151A05-8 Ver.2.4).
Main features of the TCL LED40D2900S device:
The matrix (LED panel) LSC400HN02-802 is installed.
To power the backlight LEDs, a converter is used, combined with the TP.S512.PB775 main board, controlled by the GB98AERN PWM controller. As power elements of the LED driver, keys of the TO-252 type are used.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT23-6 microcircuits and TO-220 type power switches.
MainBoard - the main board (motherboard) is a TP.S512.PB775 module, using CPU chips: 9206B, SPI Flash: GD25Q64, TPA3110LD2 and others.
The DVB + SAT tuner provides television reception and channel tuning.