Technical description and composition of the MYSTERY MTV-3227LT2 TV, type of panel and applicable modules. The composition of the modules.MYSTERY LED
Model: MTV-3227LT2
Chassis / Version: MT31LB
Panel: LVW320CSOT E45 V11 720p HD, 1366x768
LED driver (backlight): integrated into PSU
PWM LED driver: MP3394S
MOSFET LED driver: APM1105N, AOD442
Power Supply (PSU): SHG3206A-101H
PWM Power: LD7750RGR, MC34063A
MainBoard: MT31LB (40-T31TOT-MAB2HG)
IC MainBoard: SPI Flash: 25Q64F;
Tuner: RF221ZN V4D17AA
Technical Specifications MTV-3227LT2
MYSTERY MTV-3227LT2
General repair guidelines for TV LCD LED
Possible malfunctions
- The MYSTERY MTV-3227LT2 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.
With such manifestations, the SHG3206A-101H power module usually fails. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches and rectifier diodes for a possible partial or complete 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.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers LD7750RGR, MC34063A, in the absence of visible damage or frank fault between the terminals, are checked by replacing with new ones, or obviously working.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
Often in such cases, there is no LED backlight. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
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 MT31LB 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). Board repair and chip replacement SPI Flash: 25Q64F; are made in the presence of the necessary equipment and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
If the TV works normally from external devices, but does not tune into television channels, the tuner RF221ZN V4D17AA 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.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.
FIRMWARE FOR SPI FLASH -----------> MYSTERY MTV-3227LT2, Main: MT31LB (40-T31TOT-MAB2HG), Panel: 720p HD, 1366x768
To reduce the backlight current in LED drivers with the MP3394S (MP3394) controller, increase the resistance of the resistor from pin 6 (ISET) to the chassis. The maximum current in each channel (in milliamperes) for the Rset resistor (in kilo-ohms) is determined from the ratio 790 * 1.23V / (Rset + 0.4).
Repair MainBoardThe appearance of the MainBoard MT31LB is shown in the figure below:
MT31LB
The appearance of the power supply
Main features of the MYSTERY MTV-3227LT2 device:
Installed matrix (LED-panel) LVW320CSOT E45 V11 720p HD, 1366x768.
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the MP3394S PWM controller. As power elements of the LED driver, keys of the type APM1105N, AOD442 are used.
The necessary supply voltages for all nodes of the MYSTERY MTV-3227LT2 television are generated by the SHG3206A-101H power supply module or its analogs using LD7750RGR, MC34063A microcircuits.
MainBoard - the main board (motherboard) is an MT31LB module, using SPI Flash chips: 25Q64F; and others.
The tuner RF221ZN V4D17AA provides the reception of television programs and tuning to channels.
TV MYSTERY MTV-3227LT2 with LCD display LVW320CSOT, diagonal size 32 "(81 cm) 16: 9 format. The required brightness of the screen 280 cd / m² is provided by LED backlight LED. Contrast, as the ratio of maximum brightness to minimum, is 4000: 1. LED TV backlighting technology is implemented in the manufacturing technology of the screen of this model of the TV. 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 . Alogovyh systems PAL, SECAM, NTSC Image processing and the formation of the digital signal is in 480i standards, 480p, 576i, 576p, 720p, 1080i, 1080p Supported multimedia file formats:. MP3, MPEG4, MKV, JPEG.
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), component, VGA, HDMI x2, MHL, 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, 1280x1024, 1360x768.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-T2 standards.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The LVW320CSOT E45 panel of the MYSTERY MTV-3227LT2 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.
