Tuesday, 28 April 2020

REPAIR / SERVICING TV MYSTERY MTV-1922LW

Technical description and composition of the MYSTERY MTV-1922LW TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-1922LW
Chassis / Version: V3L08
Panel: V185B1-L17
LED driver (backlight): integrated into MainBoard
PWM LED driver: AP3039AM, AP3608E
Power Supply (PSU): integrated into MainBoard
PWM Power: OB2273 (PWM SOT23-6)
MainBoard: MSTV2407-ZC01-01
IC MainBoard: Cpu: MST6E181VS-LF-Z1, Spi Flash: MX25L3206E, Eeprom: 24C16, Audio: TPA3113D2
Tuner: F35WT-2A-E
Control: Service Login: INPUT 2580
Technical Specifications MTV-1922LW
MYSTERY MTV-1922LW
General repair guidelines for TV LCD LED
It is advisable to start the repair of the MYSTERY MTV-1922LW TV with a careful external examination of both internal and external elements. Specific external damage to some elements can sometimes indicate further actions to determine the malfunction of the TV and localize the defect before the necessary measurements are taken. Experienced repairmen are often aware of the causes of the defect and the possible consequences, for example, from ring cracks in the soldering of the leads of the elements, as well as from swollen capacitors or resistors burnt to coal dust and other external indirect signs.
In case of a power supply module malfunction, external manifestations may be different, for example, the MYSTERY MTV-1922LW does not turn on at all and there is no indication of the indicator lights on the front panel. With the same symptoms, the stabilizer (converter) of the power supply to the control processor may be faulty. When repairing the power supply, it is advisable to start the diagnostics by checking the mains fuse and the electrolytic capacitors of the filters of the converter secondary rectifiers. In the event of a fuse breaking, the reason should be sought in the power semiconductor elements of the pulse converter of the main power supply. First of all, it is necessary to check the diodes of the rectifier bridge of the mains voltage and the power switch (s) of the converter.
If a breakdown of the power switch is detected, it should be remembered that in a switching power supply (IIP) it does not fail by itself without any reasons that should be sought by checking other elements of the primary circuit - electrolytic capacitors, a PWM controller, which can only be checked replacement, as well as other semiconductor elements (diodes, transistors, zener diodes).
If the MYSTERY MTV-1922LW does not have an image, but there is sound and the TV is controlled by the remote control, a malfunction in the backlight circuits of the V185B1-L17 panel is likely. The LEDs or the power converter - LED driver may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the LED driver, and check the LEDs, connecting obviously known good diagnostics.
A malfunction in the backlight circuits often occurs due to an open in the power circuit of the LED lines. It requires disassembling the panel and checking the LEDs themselves, the rations of their terminals, as well as the reliability of the connections in the connectors and rations of the terminals.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source.
Repair or diagnostics of the MSTV2407-ZC01-01 motherboard should begin by checking the stabilizers or power converters of its microcircuits. If necessary, you should update the software (software).
In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its SPI FLASH EN25Q32 chips and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
If there is no reception of television channels, but the TV works properly from external devices, first of all it is necessary to check the voltage of the varicaps of the tuner F35WT-2A-E, which is usually within 30-33V, as well as other supply voltages at the terminals of the tuner.
Owners and users of the MYSTERY MTV-1922LW 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!


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    MYSTERY Main MSTV2407-ZC01-01

FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-1922LW(V3L08), Main MSTV2407-ZC01-01, Panel V185B1-L17



 In cases where a failure has occurred in Winbond's SPI FLASH software, we recommend replacing the chip with a new one. Often, faulty Winbond microcircuits can temporarily restore their functionality after temperature exposure, for example, when a soldering station is heated by a hairdryer. Sometimes this is enough to read the regular contents of the software.

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 MSTV2407-ZC01-01 is shown in the figure below:
MSTV2407-ZC01-01
MSTV2407-ZC01-01 motherboard is combined with a power module. The processor is MST6E182VG, or MST6E181VG, made using BGA technology. Repair of the power module is carried out according to conventional technology, starting with checking its power elements. The following is a functional check of the converters for the processor power: + 1.3V, + 1.8V, 3.3V, based on SY8008B PWM controllers. The power supply of the built-in DDR 2.5V is generated from a 3.3V source using the P-N junction of the 1N4001 diode (3.3V-0.8V = 2.5V). Standby mode is organized from the linear stabilizer series 1117-3V3. The LCD panel is powered by either 5V or 12V, depending on the type of panel used.
MSTV2407-ZC01-01 can be used in TVs:
BBK LEM2249HD Ver2 (Panel LM215DT5D), BBK LEM2284F (Panel M215HG-LE4 Rev. C3), BBK LEM2681F (Panel V260H1-LE10 Rev. C1), BBK LEM2682 LEM2682DT (Panel V260B2-LE11 Rev.C1V320WX LEMC -200), Haier LE32T1000 (Panel T320XVN09.0), MYSTERY MTV-2224LW (Panel M215HG-LE4 Rev. C3), MYSTERY MTV-3222LW (Panel T320XVN01.0), MYSTERY MTV-1924LW (Panel V185B1-L17), MTV-3018LW (Panel V290BJ1-PE1), MYSTERY MTV-1911LW (Panel HT185WX7-100), MYSTERY MTV-1922LW (Panel V185B1-L17), MYSTERY MTV-1913LW (Panel HT185WX7-100), MYSTERY MTW232 -20A), MYSTERY MTV-1918LW (Panel V185B1-L17), MYSTERY MTV-2213LW (Panel M215HGE-L10), MYSTERY MTV-2222LW (Panel M215HG-LE4 REV.C3), MYSTERY MTV-2418LW (Panel HM236W) , MYSTERY MTV-2424LW (Panel HM236WU8-100), MYSTERY MTV-1914LW (Panel V185B1-L15 Rev.c1), MYSTERY MTV-3223LW (Panel LK315T3HB94), MYSTERY MTV-2422LW (Panel HM236WYS8–3200WYSTER-32) (Panel T320XVN09.0), MYSTERY MTV-2218LW (Panel CLAA215FA10), MYSTERY MTV-19 11WL (Panel V185B1-L15 REV.C1), MYSTERY MTV-3221LW (Panel HV320WX2-268), MYSTERY MTV-2211W (Panel M215HG-LE4).
Main features of the MYSTERY MTV-1922LW device:
Installed matrix (LED-panel) V185B1-L17.
To power the backlight LEDs, a converter is used, combined with the main board MSTV2407-ZC01-01, controlled by the AP3039AM, AP3608E 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: MST6E181VS-LF-Z1, Spi Flash: MX25L3206E, Eeprom: 24C16, Audio: TPA3113D2 and others.
The F35WT-2A-E tuner provides television reception and channel tuning.

 MYSTERY MTV-1922LW TV with V185B1-L17 LCD, 19 "(48 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 . Max PAL, SECAM Image processing and the formation of the digital signal is in 480i standards, 480p, 576i, 576p, 720p, 1080i Supported multimedia file formats:. MP3, WMA, MPEG4, DivX, MKV, 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, 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 36 watts.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The panel V185B1-L17 of the MYSTERY MTV-1922LW 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.