Thursday, 30 April 2020

REPAIR / SERVICING TV MYSTERY MTV-3023LT2

Technical description and composition of the MYSTERY MTV-3023LT2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-3023LT2
Chassis / Version: MSDV3222-ZC01-01 Ver V2N10
Panel: MT3151A05
LED driver (backlight): integrated into MainBoard
PWM LED driver: AP3039AM-G1, AP3608EM
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: MSDV3222-ZC01-01
IC MainBoard: CPU: MSD308BT-SW, SPI Flash: 25Q64BV
Technical Specifications MTV-3023LT2
MYSTERY MTV-3023LT2
General repair guidelines for TV LCD LED
Diagnostics of malfunctions and repairs of MYSTERY MTV-3023LT2, as well as other electronic devices, is recommended to begin with an external examination of the external and internal elements. In some cases, visible external damage to the elements can suggest the direction of troubleshooting and localization of the defect even before the start of the necessary measurements at the control points of the nodes of electronic circuits. If charred resistors, swollen electrolytic or cermet capacitors, ring cracks in the soldered terminals of transformers or heating elements are detected, it is advisable to establish the causes and consequences of the malfunction that has arisen, as well as to check the connected elements and assemblies.
In the absence of any signs of operability, when the MYSTERY MTV-3023LT2 does not turn on and does not signal anything with the control lights on the panel, there is a possibility of a malfunction of the TV power module. With the same manifestations, the power regulator of the control processor on the motherboard may be faulty. In the absence of swollen filter capacitors of the secondary rectifiers, the diagnostics of the power supply should be started by checking the fuse and, if it is broken, it is first necessary to check all the power semiconductor elements of the primary circuit - diodes and transistors for the possibility of an avalanche or thermal breakdown.
In most cases, key breakdowns in switching power supplies (SMPS) do not occur for no reason and you should look for other faulty circuit elements that could provoke a defect. This can be dried electrolytic capacitors in the primary circuit, and faulty damper elements, as well as dangling resistors or punched semiconductor elements in the stabilization circuits. Possible defective PWM chip from the manufacturer.
If the MYSTERY MTV-3023LT2 does not have an image, but there is sound, the backlight LEDs of the MT3151A05 panel or their power converter may malfunction. You should also make sure that the electrolytic capacitors of the secondary rectifiers of the common power supply are working.
Often there is a need for disassembling the panel to check the health of the LEDs, as well as contact connections in the connectors and soldering.
An open in the LED lines connected in series cannot be detected with a multimeter or tester without disassembling the panel. To open all the transitions, several tens of volts are needed, and it is best to use a current source for such purposes.
On the motherboard MSDV3222-ZC01-01, in the event of a malfunction, you should first check the performance of all the stabilizers or power converters of the microcircuits and, if necessary, update the software (software).
When repairing an MB board, you need to check its CPU components: MSD308BT-SW, SPI Flash: 25Q64BV. Defective items should be replaced. If BGA chips are installed, their malfunction is usually localized by heating.
Remember! Attempts to self-repair by users of the MYSTERY MTV-3023LT2 TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!

FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-3023LT2, Main: MSDV3222-ZC01-01, Panel: MT3151A05

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-3023LT2 device:
Installed matrix (LED panel) MT3151A05.
To power the backlight LEDs, a converter is used, combined with the main board MSDV3222-ZC01-01, controlled by a PWM controller AP3039AM-G1, AP3608EM.
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: 25Q64BV and others.
Additional technical information about the panel:
Brand: CSOT
Model: MT3151A05-4
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: HVA, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 62%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Lamp Type: WLED
Signal Interface: LVDS (1 ch, 8-bit)
Voltage: 12.0V

 MYSTERY MTV-3023LT2 TV with MT3151A05 LCD display, diagonal size 28 "(71 cm) in 16: 9 format. The required screen brightness of 200 cd / m² is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 1000: 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). The input high-frequency or video signal can be processed in analog systems . Max 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, JPEG.
The power of the acoustic system of sound 20 W (2x10 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), AV, audio x2, VGA, HDMI x2, USB. An output for connecting headphones is provided.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: With stand 642x444x209 mm, Without stand 642x398x44 mm.
Attention! The panel of the MT3151A05 MYSTERY MTV-3023LT2 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.