Tuesday 17 March 2020

REPAIR / SERVICING TV TCL L32E3003

Technical description and composition of the TCL L32E3003 TV, panel type and applicable modules. The composition of the modules.
TCL LED
Model: L32E3003
Chassis / Version: MT31D
Panel: LVW320NDCL V2
LED driver (backlight): integrated into PSU
PWM LED driver: OB3362RP
Power Supply (PSU): 40-ES2822-PWE1XG
PWM Power: PWM SOT23-6
MOSFET Power: TO-220
MainBoard: 40-MT31TD-MAE2HG
IC MainBoard: SPI FLASH: 25Q64
Tuner: DT21WN-2-E
Technical Specifications L32E3003
TCL L32E3003
General repair guidelines for TV LCD LED
Possible malfunctions
- The TCL L32E3003 TV does not turn on, does not respond to the remote control and buttons on the control panel, does not light up or blink indicators.
With such manifestations, in some cases, the 40-ES2822-PWE1XG power module is faulty. It is necessary to measure its output voltages, and in case of their absence, check the operability of the power switches of the converters and rectifier diodes for the probability of a short circuit.
In case of breakdowns of diodes in the secondary circuits, the converter can operate in emergency short circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key usually breaks.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback circuits (OOS) of stabilization. PWM controllers (PWM), if they do not have visible damage to the chassis and open short circuit between the terminals, are usually checked by replacement.
- There is no image, there is sound, all other functions of the TV work. When turned on, the image may sometimes appear for a second.
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. The reason can be found in the malfunction of the LEDs, in the violation of the contact connections of the LED strips, or in the provision of their power (LED driver).
To check the health in the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
- 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 40-MT31TD-MAE2HG 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 components SPI FLASH: 25Q64. 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.
If the TV works normally from external devices, but does not tune into television channels, the DT21WN-2-E tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
We recommend the owners of the L32E3003 TV for repair only to qualified specialists with the necessary work experience! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences!


 FIRMWARE FOR SPI FLASH ----------->  TCL L32E3003 MT31D, Main: 40-MT31TD-MAE2HG, Panel: LVW320NDCL V2


The appearance of the MainBoard 40-MT31TD-MAE2HG is shown in the figure below:
40-MT31TD-MAE2HG
The appearance of the power supply
Main features of the TCL L32E3003 device:
Installed matrix (LED-panel) LVW320NDCL V2.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the OB3362RP PWM controller.
The necessary supply voltages for all nodes of the TCL L32E3003 TV are generated by the 40-ES2822-PWE1XG power supply module or its analogs using PWM SOT23-6 microcircuits and TO-220 type power switches.
MainBoard - the main board (motherboard) is a 40-MT31TD-MAE2HG module, using SPI FLASH chips: 25Q64 and others.
The DT21WN-2-E tuner provides television reception and channel tuning.


TCL L32E3003 TV with a LVW320NDCL LCD display, diagonal size 32 "(81 cm) in 16: 9 format. The brightness of the screen declared by the manufacturer is 400 cd / m² by LED backlighting. The LCD panel of this TV is equipped with LED backlight - Edge LED: You can view images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation descends into standards 480i, 480p, 576i, 576p, 720p, 1080i.
The power of the speaker system of sound 8 W (2x4 W) provide two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, SCART, VGA, HDMI x2, USB. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768, 1360x768.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C standards.
Overall dimensions: with stand 740x494x189 mm, without stand 740x452x105 mm.
TV mass: with stand: 5.9 kg, without stand: 5.6 kg.
Attention! The LVW320NDCL V2 panel of the TCL L32E3003 LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.