Friday 1 May 2020

REPAIR / SERVICING TV MYSTERY MTV-2215WD

Technical description and composition of the MYSTERY MTV-2215WD TV, panel type and applicable modules. The composition of the modules.
MYSTERY
Model: MTV-2215WD
Chassis / Version: V1I05
Panel: LTA216AT01 // M220Z1-L03
T-CON: M220Z1-X03
Inverter (backlight): integrated into PSU
PWM Inverter: TL494
MOSFET Inverter: STM6960
Power Supply (PSU): LS2204025 // LS1904016
PWM Power: LD7575BGS (PWM flyback)
MOSFET Power: SMK0760C
Mainboard: CV719H
IC MainBoard: MST719DE-L, EN25F40-100GCP, 24C32, TDA1517P
Tuner: TSN3311-Q
Technical Specifications MTV-2215WD
MYSTERY MTV-2215WD
General recommendations for repairing TV LCD
Possible manifestations of defects
- The MYSTERY MTV-2215WD 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.
Typically, with such manifestations, the defect is caused by faulty elements in the LS2204025 main power module. It is necessary to measure its output voltages, and if they are absent, check the operability of the power switches (SMK0760C) of the converters and rectifier diodes for a short circuit probability.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the elements of the primary circuit, the mains fuse usually 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) LD7575BGS (PWM flyback), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
These manifestations can be triggered by a power module, or by defects in the inverter, as well as a distortion of the currents in the lamps due to their uneven wear. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, it is necessary to ring in its converter the power switches for breakdown and the secondary windings of the transformers for an open.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the CV719H 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). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - MST719DE-L, EN25F40-100GCP, 24C32, TDA1517P and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
Before changing the tuner TSN3311-Q, if there is no possibility of tuning to television channels, you should make sure that there are supply voltages that must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope

Owners and users of the MYSTERY MTV-2215WD TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!


Mystery MTV-2215WD V2J01; Main: CV719H ver1.0, Power: LS2204025 ver1.0.

FIRMWARE FOR SPI FLASH  ----------->  , EEPROM MYSTERY MTV-2215WD V1I05, Main: CV719H, Vwr: V2J01

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    LS2204025 Power supply

 The appearance of the MainBoard CV719H is shown in the figure below:
CV719H
The appearance of the power supply
Main features of the MYSTERY MTV-2215WD device:
Installed matrix (LCD panel) LTA216AT01 or M220Z1-L03.
The matrix control uses the Timing Controller (T-CON) M220Z1-X03.
To power the backlight, a converter is used, combined with a power supply, controlled by a TL494 PWM controller. As power elements of the inverter, keys of the STM6960 type are used.
The necessary supply voltages for all nodes of the MYSTERY MTV-2215WD TV are generated by the LS2204025 power supply module or its analogs using LD7575BGS (PWM flyback) microcircuits and SMK0760C type power switches.
MainBoard - the main board (motherboard) is a CV719H module, using microchips MST719DE-L, EN25F40-100GCP, 24C32, TDA1517P and others.
The TSN3311-Q tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA216AT01
Type: a-Si TFT-LCD, Panel
Diagonal size: 21.6 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 477.417x268.416 mm
Surface: Hard coating (3H)
Brightness: 350 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 72%
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V
MYSTERY MTV-2215WD TV with LTA216AT01 LCD display, diagonal size 22 "(55 cm) 16:10 format. Screen brightness of 300 cd / m² is ensured by backlighting with CCFL (EEFL) fluorescent lamps. Contrast, as the ratio of maximum brightness to minimum, is 1000: 1. It is possible to view images in high quality HD at a resolution of 1680x1050 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 takes place in with 480i, 480p, 576i, 576p, 720p, 1080i standards Supported media file formats: MP3, MPEG4, VideoCD, SVCD, Picture CD, 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, SCART, VGA, HDMI. 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 72 watts.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The LTA216AT01 panel of the MYSTERY MTV-2215WD LCD TV is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!