Tuesday, 28 April 2020

REPAIR / SERVICING TV MYSTERY MTV-1921LD

Technical description and composition of the MYSTERY MTV-1921LD TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-1921LD
Chassis / Version: MSTV3208-ZC01-01
Panel: HT185WX3
Power Supply (PSU): Adapter 12V
MainBoard: MSTV3208-ZC01-01
IC MainBoard: CPU: MST6M48RHS-LF-Z1; SPI Flash: 25L3206E; Sound: TPA3113D2
Tuner: F21WT-3BAR-E
Technical Specifications MTV-1921LD
MYSTERY MTV-1921LD
General repair guidelines for TV LCD LED
Repair and diagnostics of any electronic device, in particular MYSTERY MTV-1921LD, it is advisable to start with a careful external examination of internal and external elements. Based on visible external changes in the state of the components, it is often possible to determine the direction of the troubleshooting before making the necessary measurements. If charred resistors, swollen electrolytic or cermet capacitors, ring cracks in the soldered terminals of transformers or heating elements are detected, it is advisable to establish the causes and consequences of the malfunction that has arisen, as well as to check the connected elements and assemblies.
If the MTV-1921LD TV does not turn on, does not make any sounds when it is turned on, and also no indicators light up or blink on the front panel, there is a high probability of a malfunction in the power supply module. In some cases, there may be a malfunction only in standby power. It is advisable to start the troubleshooting of the power supply module by checking the state of the electrolytic capacitors of the rectifier filters and the mains fuse. Defective capacitors should be replaced. If the mains fuse is broken, it is necessary to check first of all the power semiconductor elements - rectifier diodes and transistors, which are often found in such a state of breakdown.
If the power keys of the pulse converter are not equal, you should pay attention to other elements in their bundling, which may be the result or cause of their breakdown.
Sometimes the MYSTERY MTV-1921LD TV does not have an image, but there is sound, or the image appears and immediately disappears. In this case, there is a high probability of a malfunction of the converter of the backlight LEDs of the HT185WX3 panel, or a break in the LED circuit is possible. In such cases, first of all, it is necessary to verify the operability of the electrolytic capacitors of the filter by supplying the LED driver itself, including the PSU.
To check the health of the LEDs and contact connections in their power circuit, the panel must be disassembled.
It is impossible to check the line of series-connected LEDs without a special current source, and for this purpose it is not safe to use any voltage sources above 12V for them. Then it remains only to open the panel and check each LED separately. Usually, Chinese 9V-powered multimeters light up one LED slightly if you connect the probes in the forward direction, the red probe to the anode, and the black to the cathode.
Repair of the MSTV3208-ZC01-01 motherboard must begin with the diagnosis and verification of all linear stabilizers and power converters of its microcircuits. Sometimes it may be necessary to update the software (software) - flashing FLASH or EEPROM.
In cases of attempts to repair the MB board (SSB), it is necessary to check the health of its elements - CPU: MST6M48RHS-LF-Z1; SPI Flash: 25L3206E; Sound: TPA3113D2 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).
If the TV works normally from external devices, but does not tune into television channels, the F21WT-3BAR-E tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals. Sometimes the cause of the inoperability of the tuner may be a software failure.
Owners and users of the MYSTERY MTV-1921LD TV must 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-1921LD, Main: MSTV3208-ZC01-01, Panel: HT185WX3

 The appearance of the MainBoard MSTV3208-ZC01-01 is shown in the figure below:
The motherboard MSTV3208-ZC01-01 is made using the multifunction microprocessor MST6M48RHS-LF, which includes a scaler (graphic controller-scaler). To organize the work of the processor, the external RAM H5PS5162GFR 512Mb DDR2 SDRAM in BGA version and SPI FLASH 25Q32 (4Mb) are used. To provide power to the processor core, a DC / DC converter with an output voltage of 1.2V is used, assembled on the basis of the MP1482 PWM controller. Other nodes of the processor are powered by linear voltage stabilizers 2.5V, 3.3V. 1.8V voltage is used to power the DDR RAM, 3.3V is needed for the SPI FLASH ROM.
It is advisable to start the MainBoard repair by checking the supply voltage in Stand-by mode 5V and 3.3V. In operating mode, check the operation of all linear stabilizers and the DC / DC converter. If there is a backlight and there is no image, you need to check the power of the 5V or 12V panel (depending on the type of LCD panel), which should be present directly on the LVDS connector.
If the indicator signals Stand-by mode and does not respond to the remote control and control buttons, it is recommended to update the SPI Flash software. Taking into account the glitchiness of Winbond SPI chips, it is advisable to replace them with new ones in case of software failures.
MSTV3208-ZC01-01 can be used in TVs:
BBK LEM2648SD (Panel V260B1-LE9 revC1), BBK LEM3248SD (Panel HV320WX2-130 (B3)), BBK LMP3229HDU Ver1 (Panel T315HW02 v.7), BBK LMP3229HDU Ver2 (Panel T315HW04 V7), BBK LEM2649HD (Panel V260H1-LE7 Rev C1), MYSTERY MTV-2607W (Panel V260H1-L05), MYSTERY MTV-3206 (Panel T315XW04 V.7), MYSTERY MTV-3207W (Panel V315B3-L04 rev.c1), MYSTERY MTV-3213LW (Panel T315XW04 V.8), MYSTERY MTV-2220LW (Panel CLAA215FA15), MYSTERY MTV-3207W (Panel HV320WX2-110), MYSTERY MTV-2614LW (Panel V260H1-LE6), MYSTERY MTV-3208WH (Panel V315H1-L02), MYSTERY MTV-2411LW (Panel V236H1-LE5 Rev.C1), MYSTERY MTV-2618LW (Panel V260B2-LE11), MYSTERY MTV-2211LW (Panel CLAA215FA10), MYSTERY MTV-2414LW (Panel V236H1-L01), MYSTERY MTV-2611LW (Panel V260H1-LE6 Rev.C1), MYSTERY MTV-3206W (Panel T315XW03 V.3), MYSTERY MTV-3211LW (Panel V315H3-LE2 Rev. C1), MYSTERY MTV-4207WH (Panel T420HW09 V.1), MYSTERY MTV-1921LD (Panel HT185WX3).
Main features of the MYSTERY MTV-1921LD device:
Installed matrix (LED-panel) HT185WX3.
To power all the internal components of the MYSTERY MTV-1921LD TV, an external adapter 12V type is used.
MainBoard - the main board (motherboard) is an MSTV3208-ZC01-01 module, using CPU chips: MST6M48RHS-LF-Z1; SPI Flash: 25L3206E; Sound: TPA3113D2 and others.
The F21WT-3BAR-E tuner provides television reception and channel tuning.
The MYSTERY MTV-1921LD TV with an HT185WX3 LCD display, 19 "(48 cm) diagonal size in 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. Edge LED backlighting is realized 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 an analog system . Ah PAL, SECAM, NTSC Image processing and the formation of the digital signal is in 480i standards, 480p, 576i, 576p, 720p, 1080i, 1080p Supported multimedia file formats:. MP3, MPEG4, VideoCD, SVCD, 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 40 watts.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The panel of the HT185WX3 MYSTERY MTV-1921LD LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the screen surface 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.