Wednesday, 29 April 2020

REPAIR / SERVICING TV MYSTERY MTV-2429LTA2

Technical description and composition of the MYSTERY MTV-2429LTA2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-2429LTA2
Chassis / Version: MS63083-ZC01-01
Panel: V236BJ1-P01
LED driver (backlight): integrated into PSU
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: MS63083-ZC01-01 & IP4000-ZC01-01
IC MainBoard: AML8726-MX, 29F64G08CBABA, 25Q32
Tuner: LHD
Technical Specifications MTV-2429LTA2
MYSTERY MTV-2429LTA2
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The MYSTERY MTV-2429LTA2 TV does not turn on and does not show any signs of operability at all. There is no reaction to the remote control and control buttons from the front panel.
The malfunction in such cases should first be sought in the power elements of a switching power supply (IIP) - a network voltage converter (AC / DC), which in this TV model is combined with the MainBoard MS63083-ZC01-01 main board. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, it is necessary to check the serviceability of power switches and rectifier diodes for possible breakdown (short circuit).
In case of diode breakdowns 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.
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, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
The most likely in these cases is a malfunction of the LED backlight. 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, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the motherboard MS63083-ZC01-01 should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements AML8726-MX, 29F64G08CBABA, 25Q32. BGA chip malfunctions are usually easy to detect by warming up.
The malfunction of the LHD tuner is established after checking the software and all the supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
We recommend the owners of the MTV-2429LTA2 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!
Repair MainBoard
The appearance of the MainBoard MS63083-ZC01-01 is shown in the figure below:
MS63083-ZC01-01
MS63083-ZC01-01 can be used in TVs:
MYSTERY MTV-3229LTA2 (Panel V320BJ7-PE1), MYSTERY MTV-2429LTA2 (Panel V236BJ1-P01), MYSTERY MTV-3030LTA2 (Panel V290BJ1-PE1).
Main features of the MYSTERY MTV-2429LTA2 device:
Installed matrix (LED-panel) V236BJ1-P01.
To power the backlight LEDs, a converter is used, combined with a power supply.
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.
MainBoard - the main board (motherboard) is a module MS63083-ZC01-01, using microchips AML8726-MX, 29F64G08CBABA, 25Q32 and others.
The LHD tuner provides television reception and channel tuning.



Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V236BJ1-P01
Type: a-Si TFT-LCD, CELL
Diagonal size: 23.6 inch
Resolution: 1366x768, WXGA
Display Mode: MVA, Normally Black, Transmissive
Active Area: 521.471x293.184 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 5.5% (with Polarizer)
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 8.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V

MYSTERY MTV-2429LTA2 TV with V236BJ1-P01 LCD, 24 "(61 cm) diagonal size of 16: 9 format. The required screen brightness of 200 cd / m² is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 2000: 1. Edge LED backlighting is implemented in the LED-panel of this TV - Edge LED.The design and technical capabilities of the TV include watching programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphical decomposition according to the standard 1080p (Full HD).
MTV-2429LTA2 TV has built-in SMART Software and pre-installed Android Operating System. Connecting to the Internet can be done via Wi-Fi. The input high-frequency or video signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, Xvid, DivX, MKV, JPEG.
The power of the sound system 10 W (2x5 W) provides 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 x2, Ethernet (RJ-45), Wi-Fi 802.11n. An output for connecting headphones is provided. 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, 1280x1024, 1360x768, 1920x1080.

A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
The power consumed by the TV in the operating mode from the network is 50 watts.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.

Attention! The panel V236BJ1-P01 of the MYSTERY MTV-2429LTA2 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.