Wednesday, 29 April 2020

REPAIR / SERVICING TV MYSTERY MTV-2431LT2

Technical description and composition of the MYSTERY MTV-2431LT2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-2431LT2
Chassis / Version: MSDV3222-ZC01-01
Panel: V236BJ1 600
T-CON: V236BJ1-XC01; CM501, CM601, 1577, CM1801B
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: GD25Q64B, Scaller: NT71263FG-300
Technical Specifications MTV-2431LT2
MYSTERY MTV-2431LT2
General repair guidelines for TV LCD LED
TV MYSTERY MTV-2431LT2, like many other electronic devices, it is advisable to start repairing by inspecting all external and internal elements. Sometimes, based on visible changes in the components of the device, it is possible to draw some conclusions and determine the direction of further troubleshooting even before the necessary measurements are taken. Carbonized paint on the upper layer of resistors, electrolytic capacitors of rectifier filters swollen after boiling, cracked soldering at the terminals of heating elements or transformers can often suggest the cause of the defect and possible consequences.
Malfunctions of the power module can be expressed in different ways, for example, the MYSTERY MTV-2431LT2 does not turn on at all and the control lamps on its front panel do not light up and do not blink, and there are no signs of operability. It should be noted that with the same external manifestations, the processor power regulator (converter) may be faulty. It is advisable to start the troubleshooting of the power supply module by checking the state of the electrolytic capacitors of the rectifier filters and the mains fuse. Defective capacitors should be replaced. If the mains fuse is broken, it is necessary to check first of all the power semiconductor elements - rectifier diodes and transistors, which are often found in such a state of breakdown.
As a rule, the keys in switching power supplies (SMPS) are reliable enough and rarely fail for no reason to be looked for by checking other components of the circuit - electrolytic capacitors, resistors and semiconductor elements of the primary circuit. The PWM chip is verified by replacing it with a known good one.
If the MYSTERY MTV-2431LT2 has no image, there is sound and the channels are switched, there is a possibility of a malfunction in the backlight LED circuit of the V236BJ1-XC01 panel, or their power converter - LED driver. Sometimes when you turn on the image appears and disappears immediately. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the LED driver itself, including in the secondary rectifier of the main PSU.
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.
A break in the line of LEDs 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.
The motherboard MSDV3222-ZC01-01 must be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or lights up constantly. In such cases, if the converters or power regulators of the microcircuit are working, a software update may be necessary.
Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing CPU elements: MSD308BT-SW, SPI Flash: GD25Q64B, Scaller: NT71263FG-300 requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can be diagnosed by warming up.
Attention! Users and owners of MTV-2431LT2 TVs who do not have the appropriate qualifications, knowledge and experience are strongly advised against attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.

FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-2431LT2, Main: MSDV3222-ZC01-01, Panel: V236BJ1-XC01

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-2431LT2 device:
Installed matrix (LED-panel) V236BJ1 600.
The matrix control uses the Timing Controller (T-CON) V236BJ1-XC01 ;.
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: GD25Q64B, Scaller: NT71263FG-300 and others.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V236BJ1-LE2
Type: a-Si TFT-LCD, Panel
Diagonal size: 23.6 inch
Resolution: 1366x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 521.471x293.184 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 8.5 (G to G)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V

 MYSTERY MTV-2431LT2 TV with V236BJ1 LCD display, 24 "(61 cm) diagonal size in 16: 9 format. The required screen brightness of 230 cd / m² is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 1000: 1. LED TV backlighting technology is implemented in the technology for making this TV model’s screen. High quality HD images can be viewed 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 log 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, MPEG4, Xvid, MKV, JPEG.
The power of the sound system 10 W (2x5 W) provide 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 x2, 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.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: 550x375x160 mm.
TV Weight: 4 kg.
Attention! The V236BJ1 600 panel of the MYSTERY MTV-2431LT2 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.