Thursday, 30 April 2020

REPAIR / SERVICING TV MYSTERY MTV-4025LT2

Technical description and composition of the MYSTERY MTV-4025LT2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-4025LT2
Chassis / Version: TP.S512.PB83
Panel: CX400DLEDM // V400HJ6_PE1
LED driver (backlight): integrated into MainBoard
PWM LED driver: SN510P
MOSFET LED driver: AOD4454
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: TP.S512.PB83
IC MainBoard: CPU: S2T512, SPI Flash: GD25Q64B, RT9108NB
Tuner: R840 XF-3SDT-H
Technical Specifications MTV-4025LW
MYSTERY MTV-4025LT2
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The MYSTERY MTV-4025LT2 TV does not turn on, does not respond to the remote control and the control panel buttons, does not light up or blink indicators.
In this case, first of all, you should check the operability of the main power source - AC / DC network voltage converter, all of whose elements are located on the MainBoard TP.S512.PB83 board. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches and rectifier diodes in the converters for a short circuit.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback circuits (OOS) of stabilization. PWM controllers (PWM) PWM SOT23-6, if they do not have visible damage to the case and open short circuit between the terminals, are usually checked by replacement.
- 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.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To check the health in the LED circuit it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the TP.S512.PB83 motherboard should be started by checking the stabilizers and power converters needed to power the microcircuits and matrix. If necessary, update or replace the software (software). Board repair and replacement of CPU chips: S2T512, SPI Flash: GD25Q64B, RT9108NB are carried out with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
If there is no reception of television channels, but the TV is working properly from external devices, first of all it is necessary to check the voltage of the tuner R840 XF-3SDT-H and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
We recommend the owners of the MTV-4025LT2 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!

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    Main TP.S512.PB83

FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-4025LT2 , Main: TP.S512.PB83, Panel: CX400DLEDM or V400HJ6_PE1


 The appearance of MainBoard TP.S512.PB83 is shown in the figure below:
TP.S512.PB83
TP.S512.PB83 can be used in TVs:
AKAI LEA-39V51P (Panel LC390TA2A 902-P05-390H ), DEXP 40A7000 (Panel C400F13-E2-C), DEXP F39B7100E (Panel T390HVN04.0 CX390DLEDM), DEXP H32B7000C (Panel T320XVN02.9 C320X14-E2-A), DEXP F42B7000ED (Panel CX420DLEDM), DEXP F32C7000B (Panel BOEI320WU1), DEXP F32C7100B/W F32C7100 (Panel BOEI320WU1), DEXP 32A7000 (Panel BOEI320WU1), DEXP 42A7000 (Panel CX420DLEDM), DEXP F32B7000B (Panel BOEI320WU1), DEXP H39D7000E (Panel CX390DLEDM), DEXP F40B7000C (Panel C400F13-E2-C), DEXP H32B3200CD (Panel HV320WX2-201), HAIER LE28F6000T (Panel A275HD1A01-2 / LVW280CSDO E2 V2), HAIER LE32F6000T (Panel ST3151A05-8 LVW320CSDX E13 V2), MYSTERY MTV-4025LT2 (Panel CX400DLEDM), SHIVAKI STV-32LED13 (Panel SV320SHD PDL320TU2A X41), SHIVAKI STV-42LED16 (Panel V420HJ-P01), SHIVAKI STV-32LED14 (Panel CX315DLEDM AJ32TO3), SHIVAKI STV-40LED13W (Panel V400HJ6PE1-C2), SHIVAKI STV-32LED15 (Panel HV320WHB-N80), SUPRA STV-LC32T440WL (Panel C320X14-E13-H), SUPRA STV-LC32T900WL (Panel LC320TU3A), SUPRA STV-LC40T900FL (Panel 1080p Full HD 1920x1080), THOMSON T32D15DH-01B (Panel LVW320CSDX E13 V30), THOMSON T28D15DH-01B (Panel LVW280CSDE E3 V5), THOMSON T32D16DH-01W T32D16DH (Panel LVW320CSDX E19 V28), THOMSON T43D16SF-01B T43D16SF (Panel LVF430LGDO E2 V18).

Main features of the MYSTERY MTV-4025LT2 device:
Installed matrix (LED-panel) CX400DLEDM or V400HJ6_PE1.
To power the backlight LEDs, a converter is used, combined with the TP.S512.PB83 main board, controlled by the SN510P PWM controller. As power elements of the LED driver, keys of the AOD4454 type are used.
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 a TP.S512.PB83 module, using CPU chips: S2T512, SPI Flash: GD25Q64B, RT9108NB and others.
The R840 XF-3SDT-H tuner provides TV reception and channel tuning.
MYSTERY MTV-4025LW TV with LVF390CMTM LCD, 39 "(99 cm) diagonal, 16: 9 format. The required screen brightness of 300 cd / m² is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 5000: 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 with a resolution of 1920x1080 pixels in a graphic resolution of 1080p (Full HD) standard. frequency or video signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, Xvid , JPEG.
The power of the sound system 16 W (2x8 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 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, 1280x1024, 1360x768, 1920x1080.
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 LVF390CMTM E13 V5 panel of the MYSTERY MTV-4025LW 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.