Friday 1 May 2020

REPAIR / SERVICING TV MYSTERY MTV-4129LT2

Technical description and composition of the MYSTERY MTV-4129LT2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-4129LT2
Chassis / Version: V1M12
Panel: LK400D3HC34K
T-CON: DUNTK4942TP
LED driver (backlight): MSTV6M30-ZC01-01 (B) P / N: 303C6M30072
Power Supply (PSU): TV3902-ZC02-01 (C) P / N: 303C3902063
PWM Power: OB5269CP
MainBoard: MSAV3220-ZC26-02 (B) P / N: 303C3220156
IC MainBoard: CPU: MSD308BT-SW, SPI Flash: GD25Q64B, EEPROM T-con 24C16, Scaller: NT71263FG-300
Tuner: NoName
Technical Specifications MTV-4129LT2
MYSTERY MTV-4129LT2
General repair guidelines for TV LCD LED
Possible malfunctions
- The MYSTERY MTV-4129LT2 TV does not turn on, does not respond to the remote control and buttons on the control panel, does not light up or blink indicators.
Most likely in this case, the main switching power supply (IIP) TV3902-ZC02-01 is faulty. It is necessary to measure its output voltages, and in case of their absence (full or partial), it is necessary to check the serviceability of the power switches of the converters and rectifier diodes for the presence of a possible short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short-circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more 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) OB5269CP, 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 responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
Often in such cases, there is no LED backlight. 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 MSAV3220-ZC26-02 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the CPU elements: MSD308BT-SW, SPI Flash: GD25Q64B, EEPROM T-con 24C16, Scaller: NT71263FG-300. BGA chip malfunctions are usually easy to detect by warming up.
If a NoName tuner is suspected of a malfunction, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary supply voltage levels and data exchange pulses with the processor via the I2C bus at the corresponding tuner pins.
We recommend the owners of the MTV-4129LT2 TV for repair only to qualified specialists with the necessary work experience! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences!
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).
The appearance of the power supply
Main features of the MYSTERY MTV-4129LT2 device:
Installed matrix (LED panel) LK400D3HC34K.
The matrix control uses the Timing Controller (T-CON) DUNTK4942TP.
The LED driver MSTV6M30-ZC01-01 (B) is used to power the backlight LEDs.
The necessary supply voltages for all nodes of the MYSTERY MTV-4129LT2 TV are generated by the TV3902-ZC02-01 power supply module or its analogs using OB5269CP microcircuits.
MainBoard - the main board (motherboard) is an MSAV3220-ZC26-02 module, using CPU chips: MSD308BT-SW, SPI Flash: GD25Q64B, EEPROM T-con 24C16, Scaller: NT71263FG-300 and others.
The NoName tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: SHARP
Model: LK400D3HC34K
Type: a-Si TFT-LCD, CELL
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: ASV, Normally Black, Transmissive
Active Area: 885.6x498.15 mm
Surface: Antiglare, Hard coating (2H), Antireflection
Glass Depth: 0.70 + 0.70 mm
Contrast Ratio: 4000: 1
Display Colors: 1.07B (10-bit)
Response Time: 4 (G to G)
Frequency: 120Hz
Signal Interface: LVDS (4 ch, 10-bit), 92 pins
Voltage: 12.0V


MYSTERY MTV-4129LT2 TV with LK400D3HC34K LCD, 40 "(102 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 4000: 1. The LED-panel of this TV has an end LED backlight - Edge LED.The TV design and technical features include viewing programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphic resolution according to the standard 1080p (Full HD). the 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, 1080p. Supported media file formats: MP3, MPEG4, DivX, JPEG .
The power of the sound system 20 W (2x10 W) provides 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, 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, 1920x1080.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The LK400D3HC34K panel of the MYSTERY MTV-4129LT2 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.