Friday 1 May 2020

REPAIR / SERVICING TV MYSTERY MTV-4618LW

Technical description and composition of the MYSTERY MTV-4618LW TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-4618LW
Chassis / Version: MSDV3209-ZC01-01
Panel: HV460WU2-200
T-CON: HV460WUR-200 T
LED driver (backlight): integrated into PSU
PWM LED driver: OB2263, AP3616M28-G1
MOSFET LED driver: MDF0765
Power Supply (PSU): TV4205-ZC02-01
PWM Power: FAN7930, OB2273
MOSFET Power: FDPF18N50, MDF0765
MainBoard: MSDV3209-ZC01-01 (D)
IC MainBoard: CPU: MSD308PX, SPI Flash: MX25L6406EMI
Tuner: DT58WT-3RB-E
Technical Specifications MTV-4618LW
MYSTERY MTV-4618LW
General repair guidelines for TV LCD LED
Possible malfunctions
- The MYSTERY MTV-4618LW TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
In such cases, the TV4205-ZC02-01 power supply is usually faulty. Then it is necessary to measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of power switches (FDPF18N50, MDF0765) and rectifier diodes of converters for possible 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.
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) FAN7930, OB2273, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
The most likely in these cases is a malfunction of the LED backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To check the LED lines for breaks without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter, a voltage of the order of several tens of volts is required.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the motherboard MSDV3209-ZC01-01 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 - CPU: MSD308PX, SPI Flash: MX25L6406EMI 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.
If you suspect a malfunction of the DT58WT-3RB-E tuner, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary voltage levels and pulses of data exchange with the processor via the I2C bus at the corresponding terminals of the tuner.
Owners and users of the MYSTERY MTV-4618LW 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!

FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-4618LW, Main: MSDV3209-ZC01-01 (D), Panel: HV460WU2-200


 To reduce the backlight current in LED drivers with the AP3616M28-G1 terminal stage, the total resistance of the resistors from terminal 22 (ISET AP3616M28) to the housing should be proportionally increased. The maximum current in each of the 16 channels is 75 mA. To increase the current in the diodes, the channels are connected in parallel. The current in milliamperes in each channel is determined from the calculation of 1560 * 1.194 / Rset, where Rset is the resistance from the ISET output to the housing in kilo-ohms.

Repair MainBoard
The appearance of the MainBoard MSDV3209-ZC01-01 is shown in the figure below:
MainBoard MSDV3209-ZC01-01 uses a multifunctional microprocessor of the type MSD309PX or MSD308PX with an integrated scaler. Two RAM chips W9751G6IB are used as RAM. SPI Flash MX25L6406EMI-12G is made in the SOP-16 (16 pin) package.
It is advisable to start the repair of the motherboard by checking the voltage + 5V standby mode. In the operating mode, it is necessary to check the operability of linear stabilizers and power converters of the processor, memory, panel and other components of the board.
MSDV3209-ZC01-01 can be used in TVs:
BBK LEM3281FDT (Panel V315B1-LE9 REV.C1), BBK LEM3285FDTG (Panel V315H4-LE7 REV.C1), BBK LEM1949DT (Panel HT185WX3-100), BBK LEM3248DT (Panel V315B1-LE7 REV.C1), BBK LEM2665FDTG (Panel V260H1-LE8), BBK LEM3249FDT (Panel V315H4-LE8), BBK LEM2449FDT (Panel M236MWF7), BBK LEM3282DT (Panel V315B1-LEA), MYSTERY MTV-4018LW (Panel T390HVN01.0), MYSTERY MTV-4022LW (Panel M390HJ1-P01), MYSTERY MTV-4214LW (Panel T420HW08 V.5 FHD), MYSTERY MTV-3214LW (Panel V315H4-LE2 Rev.C1), MYSTERY MTV-4217LW (Panel T420HW09 V.9 (FHD)), MYSTERY MTV-3220LW (Panel V315H4-LE7).
The appearance of the power supply
Main features of the MYSTERY MTV-4618LW device:
Installed matrix (LED-panel) HV460WU2-200.
The matrix control uses the Timing Controller (T-CON) HV460WUR-200.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by the OB2263 PWM controller, AP3616M28-G1. As power elements of the LED driver, keys of the MDF0765 type are used.
The required supply voltages for all nodes of the MYSTERY MTV-4618LW TV are generated by the TV4205-ZC02-01 power supply module or its analogs using FAN7930, OB2273 microchips and power switches of the FDPF18N50, MDF0765 type.
MainBoard - the main board (motherboard) is an MSDV3209-ZC01-01 module, using CPU chips: MSD308PX, SPI Flash: MX25L6406EMI and others.
Tuner DT58WT-3RB-E provides the reception of television programs and tuning to channels.
TV MYSTERY MTV-4618LW with LCD HV460WU2-200, diagonal size 46 "(117 cm) 16: 9 format. The required brightness of the screen 400 cd / m² is provided by LED backlight LED. Contrast, as the ratio of maximum brightness to minimum, is 2000: 1. The LED-panel of this TV has end-face LED illumination - Edge LED.The design and technical capabilities of the TV include watching programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphic resolution according to the standard 1080p (Full HD). ochastotny or video signal can be processed by analog systems, PAL, SECAM, NTSC Image processing and generation of the digital signal occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p Supported multimedia 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, SCART, VGA, HDMI x2, USB. 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.
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 HV460WU2-200 panel of the MYSTERY MTV-4618LW 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.