Tuesday 17 March 2020

REPAIR / SERVICING TV TCL 19P21

Technical description and composition of the TCL 19P21 TV, panel type and applicable modules. The composition of the modules.
TCL LED  Model: 19P21
Chassis / Version: 40-MT10L1-MAE2XG
Panel: M185XW01
LED backlight: Edge LED 2 Lamp CCFL
LED driver (backlight): 40-RA1911-DRB2XG
Power Supply (PSU): PE041C0 08-PE041C0-PW200AA
MOSFET Power: MDF10N65B
MainBoard: 40-MT10L1-MAE2XG
IC MainBoard: CPU: MT5310CHOU, SPI FLASH: 32Q64-104HIP, EEPROM: 24C32WP, AUDIO: TAS5707
Tuner: DT91CT-2-E
Specifications 19P21
TCL 19P21
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The TCL 19P21 TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
In some of these cases, a fault is detected in the power module. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, check the serviceability of power switches (MDF10N65B) and rectifier diodes for possible breakdown (short circuit).
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often 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, but there is sound, it responds to the remote. Or the image appears when you turn it on and immediately disappears
As a rule, in such cases there is no display backlight. 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, 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 complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its CPU chips: MT5310CHOU, SPI FLASH: 32Q64-104HIP, EEPROM: 24C32WP, AUDIO: TAS5707 and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
Before changing the DT91CT-2-E tuner, if it is not possible to tune to television channels, make sure that there are supply voltages that must be measured at the corresponding tuner pins and checked for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
TV users and owners need to remember that attempts to self-repair a TCL 19P21 TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!




 FIRMWARE FOR SPI FLASH -----------> EEPROM TCL 19P21, Main: 40-MT10L1-MAE2XG, Panel: M185XW01



 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 19P21 device:
Installed matrix (LED-panel) M185XW01.
The LED driver 40-RA1911-DRB2XG is used to power the backlight LEDs.
The required supply voltages for all nodes of the TCL 19P21 TV are generated by the PE041C0 power module, or its analogs using power switches of the MDF10N65B type.
MainBoard - the main board (motherboard) is a 40-MT10L1-MAE2XG module, using CPU chips: MT5310CHOU, SPI FLASH: 32Q64-104HIP, EEPROM: 24C32WP, AUDIO: TAS5707 and others.
The DT91CT-2-E tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: M185XW01 VJ
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, Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC)
Response Time: 3.6 / 1.4 (Tr / Td)
Frequency: 60Hz
Lamp Type: 2 pcs CCFL Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V

 TCL 19P21 TV with M185XW01 LCD, 19 "(48 cm) diagonal size in 16: 9 format. The brightness of the screen declared by the manufacturer, 250 cd / m², is realized by LED backlighting. Dynamic contrast ratio of 100,000: 1 is achieved by special control of the LEDs depending on From the illumination in the plot, the LCD panel of this TV has end-face LED backlighting - Edge LED. m decomposition according to the standard 1080p (Full HD). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported multimedia file formats: MP3, JPEG.
The power of the speaker system of sound 6 W (2x3 W.) provide two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, VGA, HDMI, 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.
The digital tuner is capable of receiving television channels in the DVB-T, DVB-C standards.
Attention! The M185XW01 panel of the TCL 19P21 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.