Saturday, 2 May 2020

REPAIR / SERVICING TV MYSTERY MTV-3029LTA2

Technical description and composition of the MYSTERY MTV-3029LTA2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY
Model: MTV-3029LTA2
Chassis / Version: V1N02
Panel: ST2751A01-1
Inverter (backlight): integrated into MainBoard
PWM Inverter: AP3608EM-G1 (20pin) AP3039AM-G1 (14pin)
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: MSDV3225-ZC01-01
IC MainBoard: SPI FLASH: 25Q64, DRAM: K4B1GT646G-BCK0
Tuner: F33WT-3DDR-E
Technical Specifications MTV-3029LTA2
MYSTERY MTV-3029LTA2
General recommendations for repairing TV LCD
Repair and diagnostics of any electronic device, in particular MYSTERY with the V1N02 chassis, it is advisable to start with a careful external examination of internal and external elements. Often, by the external signs and nature of the damage to the elements, it becomes possible to draw some conclusions and determine a further algorithm for finding a defect before making the necessary measurements at control points. Ring cracks in the soldering of the leads of the heating elements, swollen electrolytic capacitors, a charred paint layer on the resistors - all this for the repairman can be a significant clue in the assumptions about the causes and consequences of the malfunction.
If the MYSTERY MTV-3029LTA2 does not turn on, no control lights on the front panel light up or blink; therefore, there is a very high probability of a power module malfunction. In some cases, only the processor power regulator may be faulty. When repairing the power supply, it is advisable to start the diagnostics by checking the mains fuse and the electrolytic capacitors of the filters of the converter secondary rectifiers. In the event of a fuse breaking, the reason should be sought in the power semiconductor elements of the pulse converter of the main power supply. First of all, it is necessary to check the diodes of the bridge of the rectifier of the mains voltage and the power switch (s) of the converter.
Mos-Fet keys used in switching power supplies (SMPS) rarely fail for no reason to look for when checking other circuit elements. Often the breakdown is caused by malfunctions of electrolytic capacitors or semiconductor elements in the primary circuit, or by a break in the resistors in the stabilization circuits. The PWM controller chip can also cause a breakdown of the power switch of the converter.
If the MYSTERY MTV-3029LTA2 TV does not have an image, but there is sound, the malfunction should be sought in the power converter of the backlight (inverter). It is also necessary to check the serviceability of the electrolytic capacitors of the filter of the secondary rectifiers of the PSU (power supply) for excessive ESR. It should be remembered that when the protection is turned off in order to diagnose a malfunction, there is always a risk of failure of the power elements of the inverter. After repair, it is necessary to restore all standard converter protection circuits.
The motherboard MSDV3225-ZC01-01 must be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or lights up continuously. In such cases, if the converters or power regulators of the microcircuit are working, a software update may be necessary.
Attention! Users and owners of MTV-3029LTA2 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-3029LTA2 V1N02, Main: MSDV3225-ZC01-01, Panel: ST2751A01-1



In cases where a failure has occurred in Winbond's SPI FLASH software, we recommend replacing the chip with a new one. Often, faulty Winbond microcircuits can temporarily restore their functionality after temperature exposure, for example, when a soldering station is heated by a hairdryer. Sometimes this is enough to read the regular contents of the software.
Repair MainBoard
The appearance of the MainBoard MSDV3225-ZC01-01 is shown in the figure below:
MSDV3225-ZC01-01
MSDV3225-ZC01-01 can be used in TVs:
MYSTERY MTV-3029LTA2 (Panel ST2751A01-1), MYSTERY MTV-3228LTA2 (Panel LSC320AN02).
Main features of the MYSTERY MTV-3029LTA2 device:
Installed matrix (LCD panel) ST2751A01-1.
To power the backlight, a converter is used, combined with the main board MSDV3225-ZC01-01, controlled by a PWM controller AP3608EM-G1 (20pin) AP3039AM-G1 (14pin).
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 MSDV3225-ZC01-01 module, using SPI FLASH: 25Q64, DRAM: K4B1GT646G-BCK0 and others.
The F33WT-3DDR-E tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: CSOT
Model: ST2751A01-1
Type: a-Si TFT-LCD, CELL
Diagonal size: 27.5 inch
Resolution: 1366x768, WXGA
Display Mode: HVA, Normally Black, Transmissive
Active Area: 607.528x345.024 mm
Surface: Antiglare (Haze 2%), Hard coating (3H)
Glass Depth: 0.70 + 0.70 mm
Transmissivity: 7.2% (with Polarizer)
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 62%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
The MYSTERY MTV-3029LTA2 TV with an ST2751A01-1 LCD display, diagonal size 28 "(71 cm) in 16: 9 format. The required brightness of the screen is 230 cd / m² LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 1000: 1. Edge LED backlighting is implemented 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-3029LTA2 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 takes place in the 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. 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.
The power consumed by the TV in the operating mode from the network is 90 watts.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The ST2751A01-1 panel of the MYSTERY MTV-3029LTA2 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.