Wednesday 29 April 2020

REPAIR / SERVICING TV MYSTERY MTV-2824LT2

Technical description and composition of the MYSTERY MTV-2824LT2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-2824LT2
Chassis / Version: TP.MS3463S.PB801
Panel: BOEI280WX1
T-CON: HV280WX2-270
LED driver (backlight): integrated into MainBoard
PWM LED driver: SN51DP; 400 mA
MOSFET LED driver: AOD458
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MOSFET Power: TO-220
MainBoard: TP.MS3463S.PB801
IC MainBoard: CPU: MSD3463GU, SPI Flash: 25Q64B, AUDIO: OB6220VP
Tuner: XF-3SDT-H
Technical Specifications MTV-2824LT2
MYSTERY MTV-2824LT2
General repair guidelines for TV LCD LED
Possible malfunctions
- MYSTERY MTV-2824LT2 does not turn on, does not respond to buttons and remote control, indicators on the front panel do not light up and do not blink.
In such cases, the common power source, the AC / DC voltage converter, which is combined with the elements of the main board TP.MS3463S.PB801, often turns out to be faulty. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches (TO-220) and the rectifier diodes of the converters for a short circuit probability.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short-circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the main fuse and, less often, the current sensor at the source of the key are most often cut off.
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) PWM SOT23-6, 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.
A malfunction is usually most likely in these cases at the backlight nodes of the display matrix. 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 TP.MS3463S.PB801 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). In cases of attempts to repair the MB (SSB) board, it is necessary to check the health of its elements - CPU: MSD3463GU, SPI Flash: 25Q64B, AUDIO: OB6220VP which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
Before replacing the XF-3SDT-H tuner, if there is no tuning to the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
It should be remembered! Attempts to independently repair the MYSTERY MTV-2824LT2 TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!


FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-2824LT2, Main: TP.MS3463S.PB801, Panel: BOEI280WX1

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>  Trouble Shooting Chassis TP.MS3463S.PB801

 The appearance of MainBoard TP.MS3463S.PB801 is shown in the figure below:
TP.MS3463S.PB801
TP.MS3463S.PB801 can be used in TVs:
AKAI LEA-40V35M (Panel LSC400HM06), AKIRA 32LED38T2P (Panel ST3151A05-8), AKIRA 32LED02T2M (Panel ST3151A04-9 Ver.2.1), BBK 32LEM-1029/TS2C (Panel C320X16-E18-H), BBK 39LEM-1033/TS2C (Panel C390X15-E8-A G01), BBK 32LEM-1026/TS2C (Panel CX315DLEDM ST3151A05-8), BBK 32LEM-1027/TS2C (Panel ST3151A05-8 / CX315DLEDM), DEXP F43C7100K (Panel LC430DUY (SH)(A1)), DEXP F42B7000M (Panel V420HJ2-P01), DEXP F43C7000C (Panel C430F14-E1-L / LC430DUY), DEXP F40B7100K (Panel LSC400HN02-G02 40N06-L-HPX1F1), DEXP H28C7100C (Panel C275X15-E1-H (G31)), DEXP H32C7300K (Panel LSC320AN02), DEXP H32D7100C (Panel ST3151A05-8 Ver2.5), DEXP H28D7300K (Panel HV280WX2-260), ERISSON 32LES78T2W (Panel KM0320LDRH0037), ERISSON 32LEE30T2 (Panel LK315T3HB87-12V), SUPRA STV-LC32T560WL (Panel LSC320AN10), SUPRA STV-LC32T550WL (Panel LSC320AN02), SUPRA STV-LC40T500WL (Panel C39X15-E7-A), TELEFUNKEN TF-LED32S45T2 (Panel LK315T3HB87-12V), THOMSON T39D20DH-01B (Panel T390XVN01.0).
Main features of the MYSTERY MTV-2824LT2 device:
Installed matrix (LED-panel) BOEI280WX1.
The matrix control uses the Timing Controller (T-CON) HV280WX2-270.
To power the backlight LEDs, a converter is used, combined with the main board TP.MS3463S.PB801, controlled by the SN51DP PWM controller; 400 mA As power elements of the LED driver, keys of the AOD458 type are used.
The power module is combined with the MainBoard and is designed according to a flyback AC / DC voltage converter using PWM SOT23-6 microcircuits and TO-220 type power switches.
MainBoard - the main board (motherboard) is a TP.MS3463S.PB801 module, using CPU chips: MSD3463GU, SPI Flash: 25Q64B, AUDIO: OB6220VP and others.
The XF-3SDT-H tuner allows you to receive television programs and tune to channels.
MYSTERY MTV-2824LT2 TV with a BOEI280WX1 LCD display, diagonal size 28 "(71 cm) in 16: 9 format. The required brightness of the screen is 250 cd / m² by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 2000: 1. LED TV backlighting technology is implemented in the TV screen manufacturing technology of this TV model. HD images can be viewed in high resolution at 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). Supported media file formats: MP3, MPEG4, JPEG.
The power of the sound system 12 W (2x6 W) provides 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, component, VGA, HDMI x3, USB. An output for connecting headphones is provided.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Attention! The BOEI280WX1 panel of the MYSTERY MTV-2824LT2 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.