Thursday, 30 April 2020

REPAIR / SERVICING TV MYSTERY MTV-3022LW

Technical description and composition of the MYSTERY MTV-3022LW TV, panel type and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-3022LW
Chassis / Version: MSTV2409-ZC01-01
Panel: V290BJ1-PE1
LED driver (backlight): integrated into MainBoard
PWM LED driver: AP3039AM-G1, AP3608EM
MOSFET LED driver: MDD1951
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: MSTV2409-ZC01-01
IC MainBoard: SPI Flash: 24Q32BSIG, PT2308-S
Technical Specifications MTV-3022LW
MYSTERY MTV-3022LW
General repair guidelines for TV LCD LED
Repair and diagnostics of any electronic device, in particular MYSTERY MTV-3022LW, it is advisable to start with a careful external examination of internal and external elements. Specific external damage to some elements can sometimes indicate further actions to determine the malfunction of the TV and localize the defect before the necessary measurements are taken. If ring cracks are detected in the soldering of the terminals of the elements or dangling connecting tracks, swollen capacitors or charred resistors - all this can be characteristic signs of the causes or consequences of the already known typical malfunction.
Malfunctions of the power module can be expressed in different ways, for example, the MYSTERY MTV-3022LW 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. In the absence of swollen filter capacitors of the secondary rectifiers, the diagnostics of the power supply should be started by checking the fuse and, if it is broken, it is first necessary to check all the power semiconductor elements of the primary circuit - diodes and transistors for the possibility of an avalanche or thermal breakdown.
Mos-Fet keys used in switching power supplies (SMPS) rarely fail for no reason to look for when checking other circuit elements. Often the breakdown is caused by malfunctions of electrolytic capacitors or semiconductor elements in the primary circuit, or by a break in the resistors in the stabilization circuits. The PWM controller chip can also cause a breakdown of the power switch of the converter.
If the MYSTERY MTV-3022LW 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 V290BJ1-PE1 panel, or their power converter - LED driver. Sometimes, when turned on, the image appears and immediately disappears. 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.
In case of breaks in the LED circuit, a complete disassembly of the panel is required, the LEDs are checked for an open circuit, as well as the reliability of the connections in the connectors and rations of the terminals.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes.
Diagnostics and repair of the MSTV2409-ZC01-01 motherboard usually begins with a test of the performance of the stabilizers and power converters of the module chips. In some cases, a software update is required.
In cases of complex repairs of MB (SSB) and with the necessary skills and equipment, sometimes it may be necessary to replace its SPI Flash chips: 24Q32BSIG; and other possible malfunctioning components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
We recommend the owners of the MTV-3022LW TV for repair only to qualified specialists with experience! Self-repair attempts without the appropriate knowledge and skills can lead to serious negative consequences!

FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-3022LW, Main: MSTV2409-ZC01-01, Panel: V290BJ1-PE1



 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 MSTV2409-ZC01-01 is shown in the figure below:
MSTV2409-ZC01-01
MSTV2409-ZC01-01 can be used in TVs:
BBK LEM1961 (Panel HM185WX1-400), Haier LE32M600 (Panel LK315T3HB94), Haier LE24M600F (Panel M240HTN01.0), HAIER LE22M600F (Panel LC215DT8A), HAIER LE24M660 (Panel V236BJ1-P03), MYSTERY MTV-3022LW (Panel V290BJ1-PE1), MYSTERY MTV-1923LW (Panel HM185WX3-400).
Main features of the MYSTERY MTV-3022LW device:
Installed matrix (LED-panel) V290BJ1-PE1.
To power the backlight LEDs, a converter is used, combined with the main board MSTV2409-ZC01-01, controlled by the AP3039AM-G1, AP3608EM PWM controller. As the power elements of the LED driver, keys of the MDD1951 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 an MSTV2409-ZC01-01 module, using SPI Flash chips: 24Q32BSIG, PT2308-S and others.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V290BJ1-PE1
Type: a-Si TFT-LCD, CELL
Diagonal size: 29.0 inch
Resolution: 1366x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 631.092x354.816 mm
Surface: Antiglare (Haze 1%)
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 5.4% (with Polarizer)
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit)
Response Time: 9.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
MYSTERY MTV-3022LW TV with V290BJ1-PE1 LCD display, diagonal size 29 "(74 cm), 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 2000: 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). The input high-frequency or video signal can be processed in analog 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, 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, 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, 1360x768.
The power consumed by the TV in the operating mode from the network is 40 watts.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The V290BJ1-PE1 panel of the MYSTERY MTV-3022LW 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.