Technical description and composition of the MYSTERY MTV-4028LTA2 TV, panel type and applicable modules. The composition of the modules.MYSTERY LED
Model: MTV-4028LTA2
Chassis / Version: MSAV3220-ZC26-02
Panel: V390HJ1-P02
T-CON: V390HJ1-XC01
LED driver (backlight): integrated into PSU
PWM LED driver: OB2263, AP3616M28-G1
MOSFET LED driver: MDF0765 (7A 600V)
Power Supply (PSU): TV4205-ZC02-01 M23 / G44166 / 02
PWM Power: FAN7930 (PFC), OB2273
MOSFET Power: FDPF18N50
MainBoard: MSAV3220-ZC26-02 (B)
IC MainBoard: CPU MSD308BT; DRAM: K4B1G1646G; SPI: 25Q64, 25Q32, 25L4005
Tuner: YC
Technical Specifications MTV-4028LTA2
MYSTERY MTV-4028LTA2
General repair guidelines for TV LCD LED
Repair of the MYSTERY MTV4028LTA2 TV should begin with a careful external examination of all its components and modules. Visible damage to elements can sometimes indicate the direction of the search for a defect even before the necessary measurements are taken. 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.
If the MTV4028LTA2 TV does not turn on, does not make any sounds when it is turned on, and also no indicators on the front panel light or blink - there is a high probability of a malfunction in the power supply module. In some cases, only the stabilizer or power converter of the control processor may be faulty, which is typical for some MYSTERY models. In the general case, first of all, it is necessary to check the electrolytic capacitors of the secondary rectifier filters and the fuse at the input of the network. If it is broken, then you should check for breakdown of the PN junctions of the rectifier bridge diodes and the key transistor of the converter, which can either be on a separate radiator or integrated with a PWM controller in a common chip. Possible options.
If a breakdown of the power switch is detected, it should be remembered that in a switching power supply (IIP) it does not fail by itself without any reasons that should be sought by checking other elements of the primary circuit - electrolytic capacitors, a PWM controller, which can only be checked replacement, as well as other semiconductor elements (diodes, transistors, zener diodes).
If there is no image when you turn on the MYSTERY MTV4028LTA2, or it appears for a second and disappears, but there is sound, most likely there is a malfunction in the backlight LED circuit of the V390HJ1-P02 panel, or in their power converter. It is necessary to check the electrolytic capacitors of the filter of the secondary rectifiers in the general power supply unit.
To check the health of the LEDs, as well as contact connections in the ruler circuit, it is necessary to disassemble the panel.
It should be remembered that it is not possible to determine the open circuit in the LED lines without disassembling the panels with a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required.
If the motherboard MSAV3220-ZC26-02 (B) is faulty, first of all it is necessary to check all the linear stabilizers or power converters of its chips, and also, if necessary, update the software. Sometimes you can check the health of MB only by replacement.
If it is not possible to replace the MB board (SSB), you need to check the health of its elements - 25Q64, 25Q32, 25L4005. Defective components should be replaced.
Attention! Users and owners of MTV4028LTA2 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 MTV4028LTA2, Main: MSAV3220-ZC26-02 (B), Panel: V390HJ1-P02
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> TV4205-ZC02-01 Schematic diagram
To reduce the backlight current in LED drivers with the AP3616M28-G1 terminal stage, the total resistance of the resistors from terminal 22 (ISET AP3616M28) to the housing should be proportionally increased. The maximum current in each of the 16 channels is 75 mA. To increase the current in the diodes, the channels are connected in parallel. The current in milliamperes in each channel is determined from the calculation of 1560 * 1.194 / Rset, where Rset is the resistance from the ISET output to the housing in kilo-ohms.Repair MainBoard
The appearance of the MainBoard MSAV3220-ZC26-02 (B) is shown in the figure below:
MSAV3220-ZC26-02
MSAV3220-ZC26-02 can be used in TVs:
BBK LEM3284DT2 (Panel LSC320AN02), MYSTERY MTV-2224LT2 (Panel CLAA215FA10), MYSTERY MTV-4028LTA2 (Panel V390HJ1-P02), MYSTERY MTV-4829LTA2 (Panel LSC480HN02-G), MYSTERY MTV-4129LT2 (Panel LK400D3HC34K), MYSTERY MTV-2424LT2 (Panel HM236WU8-200 ), MYSTERY MTV-4030LT2 (Panel V400HJ6-PE1), MYSTERY MTV-4629LTA2 (Panel HV460WU2-200).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the TV4205-ZC02-01 module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the FAN7930 PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering were applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the network capacitor indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the MYSTERY MTV-4028LTA2 device:
Installed matrix (LED panel) V390HJ1-P02.
The matrix control uses the Timing Controller (T-CON) V390HJ1-XC01.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by the OB2263 PWM controller, AP3616M28-G1. As power elements of the LED driver, keys of the type MDF0765 (7A 600V) are used.
The required supply voltages for all nodes of the MYSTERY MTV-4028LTA2 television are generated by the TV4205-ZC02-01 power supply module or its analogs using FAN7930 (PFC), OB2273 microchips and FDPF18N50 type power switches.
MainBoard - the main board (motherboard) is an MSAV3220-ZC26-02 module, using the MSD308BT CPU chips; DRAM: K4B1G1646G; SPI: 25Q64, 25Q32, 25L4005 and others.
The YC tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V390HJ1-P02
Type: a-Si TFT-LCD, CELL
Diagonal size: 39 inch
Resolution: 1920x1080, FHD
Display Mode: MVA, Normally Black, Transmissive
Active Area: 853.92x480.33 mm
Surface: Antiglare (Haze 3.5%), Hard coating (3H)
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 5.8% (with Polarizer)
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit)
Response Time: 8.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
MYSTERY MTV-4028LTA2 TV with V390HJ1-P02 LCD, 39 "(99 cm) diagonal size of 16: 9 format. The required screen brightness of 250 cd / m² is provided by 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-4028LTA2 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 occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: MP3, WMA, MPEG4, Xvid, DivX, MKV, 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 x2, Ethernet (RJ-45), Wi-Fi. An output for connecting headphones is provided. To connect a computer or laptop to this TV model, use the VGA (D-Sub 15) 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: With stand 642x444x209 mm, Without stand 642x398x44 mm.
Attention! The panel V390HJ1-P02 of the MYSTERY MTV-4028LTA2 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.