Wednesday, 29 April 2020

REPAIR / SERVICING TV MYSTERY MTV-2618LW

Technical description and composition of the MYSTERY MTV-2618LW TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-2618LW
Chassis / Version: V2M01
Panel: V260B2-LE11
LED driver (backlight): integrated into MainBoard
PWM LED driver: AP3039AM, AP3608EM-G1
Power Supply (PSU): integrated into MainBoard
PWM Power: OB2273 (PWM SOT23-6)
MainBoard: MSTV2407-ZC01-01 // MSTV3208-ZC01-01
IC MainBoard: CPU: MST6E182VG-LF-Z1, SPI FLASH: Winbond 25Q32BVS1G, Eeprom: 24C16, Sound: TDA1517
Tuner: F35WT-2A-E
Technical Specifications MTV-2618LW
MYSTERY MTV-2618LW
General repair guidelines for TV LCD LED
Repair of electronic equipment usually begins with its external inspection and diagnosis of the malfunction. In this case, you should examine all the internal components of the MYSTERY MTV-2618LW TV, as well as the external elements of the case. Sometimes, based on visible changes in the components of the device, it is possible to draw some conclusions and determine the direction of further troubleshooting even before the necessary measurements are taken. Ring cracks in the soldering of the leads of the heating elements, swollen electrolytic capacitors, a charred paint layer on the resistors - all this for the repairman can be a significant clue in the assumptions about the causes and consequences of the malfunction.
In the absence of any signs of operability, when the MYSTERY MTV-2618LW does not turn on and does not signal anything with the control lights on the panel, there is a possibility of a malfunction of the TV power module. With the same manifestations, the power regulator of the control processor on the motherboard may be faulty. When diagnosing and repairing the power supply, first of all, replace the swollen capacitors of the filter of the secondary rectifiers and check the fuse and, if it is broken, it is necessary to identify the cause. Often in such cases, an avalanche (thermal) breakdown is detected in the power semiconductor elements of the module — rectifier diodes and transistors in the primary circuit.
In most cases, key breakdowns in switching power supplies (SMPS) do not occur for no reason and you should look for other faulty circuit elements that could provoke a defect. This can be dried electrolytic capacitors in the primary circuit, and faulty damper elements, as well as dangling resistors or punched semiconductor elements in the stabilization circuits. Possible defective PWM chip from the manufacturer.
If the MYSTERY MTV-2618LW does not have an image, there is sound and the channels switch, there is a possibility of a malfunction in the backlight LED circuit of the V260B2-LE11 panel, or their power converter - LED driver. Sometimes when you turn on the image appears and disappears immediately. 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.
To check the health of the LEDs and contact connections in their power circuit, the panel must be disassembled.
A break in the line of LEDs connected in series cannot be detected with a multimeter or tester without disassembling the panel. To open all the transitions, several tens of volts are needed, and it is best to use a current source for such purposes.
Repair or diagnostics of the MSTV3208-ZC01-01 motherboard should begin by checking the stabilizers or power converters of its microcircuits. If necessary, you should update 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: MST6E48RHS-LF-Z1, SPI FLASH: S25FL032K 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.
Once again, remind users! Attempts to self-repair a TV MYSTERY MTV-2618LW without the appropriate qualifications and experience can lead to its complete non-repairability!

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    MYSTERY MTV-2618LW V1L04, Main MSTV3208-ZC01-01, Panel: V260B2-LE11

 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 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-2618LW device:
Installed matrix (LED-panel) V260B2-LE11.
To power the backlight LEDs, a converter is used, combined with the main board MSTV2407-ZC01-01, controlled by the AP3039AM, AP3608EM-G1 PWM controller.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using OB2273 microcircuits (PWM SOT23-6).
MainBoard - the main board (motherboard) is an MSTV2407-ZC01-01 module, using CPU chips: MST6E182VG-LF-Z1, SPI FLASH: Winbond 25Q32BVS1G, Eeprom: 24C16, Sound: TDA1517 and others.
The F35WT-2A-E tuner provides television reception and channel tuning.


 MYSTERY MTV-2618LW TV with V260B2-LE11 LCD, 26 "(66 cm) diagonal size of 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 for graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, graphic processing and digital signal generation are performed in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, MPEG4, JPEG.
The power of the acoustic system of sound 6 W (2x3 W) provide two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, 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 50 watts.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The V260B2-LE11 panel of the MYSTERY MTV-2618LW 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.