Tuesday 17 March 2020

REPAIR / SERVICING TV TCL 19L55HC

Technical description and composition of the TCL 19L55HC TV, panel type and applicable modules. The composition of the modules.
TCL LED
Model: 19L55HC
Chassis / Version: 40-MT10L1-MAE2XG
Panel: V185B1-LE1 REV C1 1366x768 WXGA
LED backlight: EDGE LED
T-CON: M185B3-LA1-X + C
Power Supply (PSU): 40RQ-2410-PRE2XG
MainBoard: 40-MT10L1-MAE2XG
IC MainBoard: CPU: MT5310CHOU, SPI FLASH: 32Q64-104HIP, AUDIO: TAS5707
Tuner: TDTK-G731D / TDTK-G641D
Specifications 19L55HC
TCL 19L55HC
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The TCL 19L55HC TV does not turn on, does not respond to the remote control and buttons on the control panel, does not light or flash indicators.
In some of these cases, a fault is detected in the 40RQ-2410-PRE2XG power supply module. Then we recommend that you measure its output voltages and, if they are absent, you should check the health of the power switches and rectifier diodes of the converters for a probable short circuit.
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.
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, but there is sound, it responds to the remote. Or the image appears when you turn it on and immediately disappears
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
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 TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the 40-MT10L1-MAE2XG 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 attempts to repair the MB (SSB) board, it is necessary to check the health of its elements - CPU: MT5310CHOU, SPI FLASH: 32Q64-104HIP, AUDIO: TAS5707 which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
If the TDTK-G731D / TDTK-G641D tuner is suspected of malfunction, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary voltage levels and the data exchange pulses with the processor via the I2C bus on the corresponding tuner pins.
TV users and owners must remember that attempts to self-repair a TCL 19L55HC TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!




 FIRMWARE FOR SPI FLASH ----------->  TCL 19L55HC, Main: 40-MT10L1-MAE2XG, Panel: V185B1-LE1 REV C



 The appearance of the MainBoard 40-MT10L1-MAE2XG is shown in the figure below:
40-MT10L1-MAE2XG
40-MT10L1-MAE2XG can be used in TVs:
TCL 19L55HC (Panel V185B1-LE1 REV C1 1366x768 WXGA), TCL 19P21 (Panel M185XW01).
Main features of the TCL 19L55HC device:
Installed matrix (LED-panel) V185B1-LE1 REV C1 1366x768 WXGA.
The matrix control uses the Timing Controller (T-CON) M185B3-LA1-X + C.
The formation of the necessary supply voltages for all nodes of the TCL 19L55HC TV is carried out by the 40RQ-2410-PRE2XG power supply module, or its analogues.
MainBoard - the main board (motherboard) is a 40-MT10L1-MAE2XG module using CPU chips: MT5310CHOU, SPI FLASH: 32Q64-104HIP, AUDIO: TAS5707 and others.
The tuner TDTK-G731D / TDTK-G641D provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CMO
Model: V185B1-LE1
Type: a-Si TFT-LCD, Panel
Diagonal size: 18.5 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 409.8x230.4 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit), CIE1931 70%
Response Time: 1.3 / 3.7 (Tr / Td)
Frequency: 60Hz
Lamp Type: 13S8P WLED Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V

 TCL 19L55HC TV with V185B1-LE1 LCD display, 19 "(48 cm) diagonal size in 16: 9 format. The brightness of the screen declared by the manufacturer, 260 cd / m² is realized by LED backlighting. The LCD panel of this TV has end-lighting from LEDs - Edge LED. You can view images in high quality HD at a resolution of 1366x768 pixels in the standard for graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM. Graphic processing and digital signal generation It comes in the standards 480i, 480p, 576i, 576p, 720p.
The power of the sound system 10 W (2x5 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), SCART, VGA, HDMI x2. 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.
A digital tuner is capable of receiving television channels in DVB-T standards.
The power consumed by the TV in the operating mode from the network is 16 watts.
Overall dimensions: 467x354x140 mm.
Attention! The panel V185B1-LE1 REV C1 1366x768 WXGA LED-TV TCL 19L55HC 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.