Technical description and composition of the MYSTERY MTV-3027LT2 TV, type of panel and applicable modules. The composition of the modules.MYSTERY LED
Model: MTV-3027LT2
Panel: LVW280CSOT E19 V1
T-CON: MT3151A05-3-XC-1; ST2751A01-4 rev2.1
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: 40-T301TOT-MAB2HG 2013-09-20
IC MainBoard: FLASH: Winbond 25Q64FVSIG, AUDIO: STA381BW
Tuner: RE221ZN (V3L05AA)
Technical Specifications MTV-3027LT2
MYSTERY MTV-3027LT2
General repair guidelines for TV LCD LED
Possible malfunctions
- The MYSTERY MTV-3027LT2 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.
Most likely in this case, the main switching power supply (IIP) SHG3206A-101H is faulty. Then it is necessary to measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of power switches and rectifier diodes of the converters for a possible short circuit.
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 keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) LD7750RGR, MC34063A, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
In most of these cases, a malfunction is detected in the nodes and backlight elements 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 blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the 40-T301TOT-MAB2HG 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). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard board - FLASH: Winbond 25Q64FVSIG, AUDIO: STA381BW. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
If there is no reception of television channels, but the TV is working properly from external devices, first of all, check the voltage of the tuner RE221ZN (V3L05AA) and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Owners and users of the MYSTERY MTV-3027LT2 TV 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!
FIRMWARE FOR SPI FLASH -----------> MYSTERY MTV-3027LT2, Main 40-T301TOT-MAB2HG 2013-09-20, Panel LVW280CSOT E19 V1
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> SHG3206A-101H Power Supply
In cases where there is a malfunction in the SPI FLASH software and a microcircuit manufacturer Winbond is installed, we recommend replacing it with a new one. Sometimes faulty SPI Winbond microcircuits can be restored for a while after being heated by a hairdryer or a lighter, which makes it possible to read the properly installed software.
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).The appearance of the power supply
Main features of the MYSTERY MTV-3027LT2 device:
Installed matrix (LED-panel) LVW280CSOT E19 V1.
The matrix control uses the Timing Controller (T-CON) MT3151A05-3-XC-1 ;.
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-3027LT2 TV are generated by the SHG3206A-101H power supply module or its analogs using LD7750RGR, MC34063A microcircuits.
MainBoard - the main board (motherboard) is a 40-T301TOT-MAB2HG module, using the FLASH chips: Winbond 25Q64FVSIG, AUDIO: STA381BW and others.
The tuner RE221ZN (V3L05AA) provides the reception of television programs and tuning to channels.
MYSTERY MTV-3027LT2 TV with LVW280CSOT LCD display, diagonal size 29 "(74 cm) in 16: 9 format. The required screen brightness of 280 cd / m² is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 3000: 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, 1920x1080.
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 LVW280CSOT E19 V1 panel of the MYSTERY MTV-3027LT2 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.
