Thursday, 30 April 2020

REPAIR / SERVICING TV MYSTERY MTV-3031LT2

Technical description and composition of the MYSTERY MTV-3031LT2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-3031LT2
Chassis / Version: V1N12
Panel: V290BJ1-PE1
LED backlight: CEN950A, CEN951A (P2000 LED-BAR_L / R 325mm 52LED)
T-CON: V290BJ1-XC01; CM1801B, CM501, CM601, P2003EV6, GT4128
LED driver (backlight): integrated into MainBoard
PWM LED driver: AP3039AM-G1, AP3608EM-G1
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: MSDV3222-ZC01-01
IC MainBoard: CPU: MSD308BT-SW, SPI Flash: GD25Q64B, EEPROM T-con 24C16, Scaller: NT71263FG-300; DRAM: H5TQ1G63DFR, Audio: MP7751
Tuner: LHD
Technical Specifications MTV-3031LT2
MYSTERY MTV-3031LT2
General repair guidelines for TV LCD LED
Possible malfunctions
- MYSTERY MTV-3031LT2 does not turn on and does not show any signs of performance at all. Does not blink indicators and does not respond to control buttons.
The malfunction in such cases, first of all, should 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 MSDV3222-ZC01-01 main board. Then we recommend that you measure its output voltages and, if they are absent, you should check the health of the power switches and rectifier diodes of the converters for a probable short circuit.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short-circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the main fuse and, less often, the current sensor at the source of the key are most often cut off.
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) PWM SOT23-6, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
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.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the motherboard MSDV3222-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: MSD308BT-SW, SPI Flash: GD25Q64B, EEPROM T-con 24C16, Scaller: NT71263FG-300; DRAM: H5TQ1G63DFR, Audio: MP7751 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.
If the TV works properly from external devices, but does not tune into television channels, the LHD tuner 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.
Attention! Users and owners of MTV-3031LT2 TVs who do not have the appropriate qualifications, knowledge and experience are strongly advised against self-repair attempts in order to avoid negative consequences that could lead to complete non-repairability of the device.


FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-3031LT2 V1N12, Main: MSDV3222-ZC01-01, Panel: V290BJ1-PE1

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    MYSTERY MTV-3224LT2 Chassis MSDV3222-ZC01-01 (MSDV3222-YL01-01)


 To reduce the backlight current in LED drivers with the AP3039AM controller and the AP3608EM terminal stage (AP3039AM-G1 & AP3608EM-G1), the AP3608EM (AP3608E) microcircuit should proportionally increase the resistor from terminal 14 (ISET) to the housing. The maximum current in each channel (in milliamperes) for the Rset resistor (in kilo-ohms) is determined from the ratio 1.194V / Rset. In channels connected in parallel, the currents add up.
Repair MainBoard
The appearance of the MainBoard MSDV3222-ZC01-01 is shown in the figure below:
The motherboard MSDV3222-ZC01-01 is made on a single chassis with a power module and an inverter to power the LED panel. The MSD308BT-SW multi-function control processor with built-in scaler is used. Repair of the power module is carried out according to standard technology - verification of power cells, electrolytic capacitors and secondary supply voltages. The following is a functional check of stabilizers and converters for powering the internal nodes of the processor and LCD panel. It should be borne in mind that if there are problems with the software in the SPI Flash chips manufactured by WINBOND, it is advisable to replace the chip itself with the contents of the software.
MSDV3222-ZC01-01 can be used in TVs:
BBK LEM3284DT2 (Panel LSC320AN02), MYSTERY MTV-2229LT2 (Panel M215HTN01.1 ), MYSTERY MTV-2429LT2 (Panel M240HTN01.2), MYSTERY MTV-2223LT2 (Panel LC215DTBA), MYSTERY MTV-2431LT2 (Panel V236BJ1 600), MYSTERY MTV-1924LT2 (Panel HT185WXF-100), MYSTERY MTV-3228LT2 (Panel LK315T3HB94), MYSTERY MTV-3023LT2 (Panel MT3151A05), MYSTERY MTV-2228LT2 (Panel RUNTK0001ZDP2), MYSTERY MTV-1929LT2 (Panel V185BJ1-PE1), MYSTERY MTV-3223LT2 (Panel LC315TU3A), MYSTERY MTV-3224LT2 (Panel HV320WX2-20A), MYSTERY MTV-3028LT2 (Panel ST2751A01-3), MYSTERY MTV-2428LT2 (Panel V236BJ1-P01), MYSTERY MTV-2424LT2 (Panel HM236WU8-200 ), MYSTERY MTV-4030LT2 (Panel V400HJ6-PE1), MYSTERY MTV-3031LT2 (Panel V290BJ1-PE1), MYSTERY MTV-3226LT2 (Panel V320BJ7-PE1).
Main features of the MYSTERY MTV-3031LT2 device:
Installed matrix (LED-panel) V290BJ1-PE1.
The matrix control uses the Timing Controller (T-CON) V290BJ1-XC01 ;.
To power the backlight LEDs, a converter is used, combined with the main board MSDV3222-ZC01-01, controlled by the AP3039AM-G1, AP3608EM-G1 PWM controller.
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 MSDV3222-ZC01-01 module, using CPU chips: MSD308BT-SW, SPI Flash: GD25Q64B, EEPROM T-con 24C16, Scaller: NT71263FG-300; DRAM: H5TQ1G63DFR, Audio: MP7751 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
The MYSTERY MTV-3031LT2 TV with a V290BJ1-PE1 LCD display, a 28 "(71 cm) diagonal size of 16: 9 format. The required screen brightness of 220 cd / m² is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 3000: 1. LED TV backlighting is implemented in the manufacturing technology of the screen of this TV model. High quality HD images can be viewed at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in tax systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i. 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 x3, USB. 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.
TV Weight: 4 kg.
Attention! The V290BJ1-PE1 panel of the MYSTERY MTV-3031LT2 LED TV is an expensive and unreliable element.
Avoid any impact on the glass.