Wednesday, 29 April 2020

REPAIR / SERVICING TV MYSTERY MTV-2422LW

Technical description and composition of the MYSTERY MTV-2422LW TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-2422LW
Chassis / Version: MSTV2407-ZC01-01
Panel: HM236WU8–100
LED driver (backlight): integrated into MainBoard
PWM LED driver: AP3039AM, AP3608EM-G1
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6 OB2273
MainBoard: MSTV2407-ZC01-01
IC MainBoard: CPU: MST6E182VG-LF; SPI Flash: EN25Q32;
Tuner: F35WT-2A-E
Technical Specifications MTV-2422LW
MYSTERY MTV-2422LW
General repair guidelines for TV LCD LED
TV MYSTERY MTV-2422LW, like many other electronic devices, it is advisable to start repairing by inspecting all external and internal elements. A visible physical change in some components can sometimes suggest a further troubleshooting direction. Ring cracks in the soldering of the leads of the heating elements, swollen electrolytic capacitors, a charred paint layer on the resistors - all this for the repairman can be a significant clue in the assumptions about the causes and consequences of the malfunction.
If the power supply module malfunctions, the external manifestations may be different, for example, the MYSTERY MTV-2422LW does not turn on at all and there is no indication of the indicator lights on the front panel. When repairing the power supply, it is advisable to start the diagnostics by checking the mains fuse and the electrolytic capacitors of the filters of the converter secondary rectifiers. In the event of a fuse breaking, the reason should be sought in the power semiconductor elements of the pulse converter of the main power supply. First of all, it is necessary to check the diodes of the rectifier bridge of the mains voltage and the power key (s) of the converter. The complete inoperability of the power supply unit can be caused by a short circuit in the power elements in the primary circuit, followed by an open fuse, or a short circuit in the loads.
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.
In those cases when the MYSTERY MTV-2422LW TV has lost an image, and the sound is there and all other functions are operational, there is a possibility of a malfunction of the LED driver (converter for powering the HM236WU8-100 panel backlight LEDs). When you turn on the TV, the image may appear briefly and disappear immediately. It must be borne in mind that with such manifestations the LEDs themselves also fail.
In most cases of lack of backlight, it becomes necessary to disassemble the panel in order to check the LEDs, connectors, loops and all contact connections. If one or several LEDs does not work in one line, therefore, they are broken and should be replaced.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts is required, and ideally, a current source.
When trying to repair the motherboard, you should first check the serviceability of linear stabilizers or power converters of microcircuits and, if necessary, update the software (software).
If it is not possible to replace the MB (SSB) card, you need to check the health of its elements - CPU: MST6E182VG-LF; SPI Flash: EN25Q32; . Defective components should be replaced.
Attention! Users and owners of MTV-2422LW 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 MTV-2422LW, Main: MSTV2407-ZC01-01, Panel: HM236WU8–100



 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 MSTV2407-ZC01-01 is shown in the figure below:
MSTV2407-ZC01-01
MSTV2407-ZC01-01 motherboard is combined with a power module. The processor is MST6E182VG, or MST6E181VG, made using BGA technology. Repair of the power module is carried out according to conventional technology, starting with checking its power elements. The following is a functional check of the converters for the processor power: + 1.3V, + 1.8V, 3.3V, based on SY8008B PWM controllers. The power supply of the built-in DDR 2.5V is generated from a 3.3V source using the P-N junction of the 1N4001 diode (3.3V-0.8V = 2.5V). Standby mode is organized from the linear stabilizer series 1117-3V3. The LCD panel is powered by either 5V or 12V, depending on the type of panel used.
MSTV2407-ZC01-01 can be used in TVs:
BBK LEM2249HD Ver2 (Panel LM215DT5D), BBK LEM2284F (Panel M215HG-LE4 Rev.C3), BBK LEM2681F (Panel V260H1-LE10 Rev. C1 ), BBK LEM2682 LEM2682DT (Panel V260B2-LE11 Rev.C1), BBK LEM3284F (Panel HV320WXC-200), Haier LE32T1000 (Panel T320XVN09.0), MYSTERY MTV-2224LW (Panel M215HG-LE4 Rev.C3), MYSTERY MTV-3222LW (Panel T320XVN01.0), MYSTERY MTV-1924LW (Panel V185B1-L17), MYSTERY MTV-3018LW (Panel V290BJ1-PE1), MYSTERY MTV-1911LW (Panel HT185WX7-100), MYSTERY MTV-1922LW (Panel V185B1-L17), MYSTERY MTV-1913LW (Panel HT185WX7-100), MYSTERY MTV-3218LW (Panel HV320WX2-20A), MYSTERY MTV-1918LW (Panel V185B1-L17), MYSTERY MTV-2213LW (Panel M215HGE-L10), MYSTERY MTV-2222LW (Panel M215HG-LE4 REV.C3), MYSTERY MTV-2418LW (Panel HM236WUA-100), MYSTERY MTV-2424LW (Panel HM236WU8-100), MYSTERY MTV-1914LW (Panel V185B1-L15 Rev.c1), MYSTERY MTV-3223LW (Panel LK315T3HB94), MYSTERY MTV-2422LW (Panel HM236WU8–100), MYSTERY MTV-3224LW (Panel T320XVN09.0), MYSTERY MTV-2218LW (Panel CLAA215FA10), MYSTERY MTV-1911WL (Panel V185B1-L15 REV.C1), MYSTERY MTV-3221LW (Panel HV320WX2-268), MYSTERY MTV-2211W (Panel M215HG-LE4 ).
Main features of the MYSTERY MTV-2422LW device:
Installed matrix (LED-panel) HM236WU8-100.
To power the backlight LEDs, a converter is used, combined with the main board MSTV2407-ZC01-01, controlled by the AP3039AM, AP3608EM-G1 PWM controller.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT23-6 OB2273 microcircuits.
MainBoard - the main board (motherboard) is an MSTV2407-ZC01-01 module, using CPU chips: MST6E182VG-LF; SPI Flash: EN25Q32; and others.
The F35WT-2A-E tuner provides television reception and channel tuning.
MYSTERY MTV-2422LW TV with HM236WU8-100 LCD, 24 "(61 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. The LED-panel of this TV has end-face LED illumination - Edge LED.The TV’s design and technical features include viewing programs and movies in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). the frequency or video signal can be processed in analogue systems PAL, SECAM. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, DivX, MKV , JPEG.
The power of the acoustic system of sound 6 W (2x3 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, S-Video, component, SCART, RGB, 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.
The power consumed by the TV in the operating mode from the network is 36 watts.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The HM236WU8-100 panel of the MYSTERY MTV-2422LW 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 unrepaired