Thursday 30 April 2020

REPAIR / SERVICING TV MYSTERY MTV-3030LTA2

Technical description and composition of the MYSTERY MTV-3030LTA2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-3030LTA2
Chassis / Version: MS63083-ZC01-01 / V1N09
Panel: V290BJ1-PE1
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: MS63083-ZC01-01
IC MainBoard: CPU: AML8726-MX, NAND Flash: MX30LF1G08AA-TI, SPI Flash: GD25Q32BSIG
Tuner: LHD
Technical Specifications MTV-3030LTA2
MYSTERY MTV-3030LTA2
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The MYSTERY MTV-3030LTA2 TV does not turn on. There are no signs of operability. The indicators on the front panel do not light or flash, the TV does not respond to the remote control and control buttons.
In such cases, the main power source - the AC / DC voltage converter, which is combined with the MainBoard MS63083-ZC01-01 board, may turn out to be faulty. It is necessary to measure its output voltages and, in case of their absence, check the serviceability of power switches and rectifier diodes in the converters for possible breakdown.
In the event of breakdowns in the secondary circuits of the converter, it can usually fail in short circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse or current sensor at the source of the key most often 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.
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.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, black to the cathode). In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- 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 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). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing CPU elements: AML8726-MX, NAND Flash: MX30LF1G08AA-TI, SPI Flash: GD25Q32BSIG requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.
Before changing the LHD tuner, if it is not possible to tune to television channels, make sure that there are supply voltages, which must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Owners and users of the MYSTERY MTV-3030LTA2 television should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!
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-3030LTA2 device:
Installed matrix (LED-panel) V290BJ1-PE1.
To power the backlight LEDs, a converter is used, combined with the main board MS63083-ZC01-01.
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 an MS63083-ZC01-01 module using CPU chips: AML8726-MX, NAND Flash: MX30LF1G08AA-TI, SPI Flash: GD25Q32BSIG and others.
The LHD tuner provides television reception and channel tuning.
Additional technical information About the panel:
Brand: CHIMEI INNOLUX
Model: V290BJ1-PE1
Type: a-Si TFT-LCD, CELL
Diagonal size: 29.0 inch
Resolution: 1366x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 631.092x354.816 mm
Surface: Antiglare (Haze 1%)
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 5.4% (with Polarizer)
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit)
Response Time: 9.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V

MYSTERY MTV-3030LTA2 TV with V290BJ1-PE1 LCD, 29 "(74 cm) diagonal, 16: 9 format. The required screen brightness of 300 cd / m² is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 2000: 1. Edge LED backlighting is realized in the LED-panel of this TV - 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).
MTV-3030LTA2 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, MKV, JPEG.
The power of the sound system 16 W (2x8 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 x2, USB, Ethernet (RJ-45), Wi-Fi 802.11g. 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, 1360x768.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: 656x428x200 mm.
Attention! The V290BJ1-PE1 panel of the MYSTERY MTV-3030LTA2 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.