Tuesday, 28 April 2020

REPAIR / SERVICING TV MYSTERY MTV-1918LW

Technical description and composition of the MYSTERY MTV-1918LW TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-1918LW
Chassis / Version: V3M02 // V2N01
Panel: V185B1-L17 // V185B1-PE1
LED backlight: 185D44-ZC14-01 (B) 30318544202; 44Led
T-CON: M185B3-L01-X + C
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: MST6E182VG-LF-Z1, FLASH: GD25Q32, Sound: TDA1517
Tuner: F35WT-2A-E
Control: IR: 303C2461231
Technical Specifications MTV-1918LW
MYSTERY MTV-1918LW
General repair guidelines for TV LCD LED
Repair of the MYSTERY MTV-1918LW TV should begin with a fault diagnosis, which involves a careful examination of the external and internal elements of the device. Visible damage to elements can sometimes indicate the direction of the search for a defect even before the necessary measurements are taken. If charred resistors, swollen electrolytic or cermet capacitors, ring cracks in the solders of the terminals of transformers or heating elements are found, 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 TV does not turn on, no indicators on its front panel are lit or blinking. Also, if the TV does not respond to the remote control and buttons, does not make any sounds or any signs of operability when turned on, there is a certain probability that the power module is defective and needs repair. Sometimes with similar manifestations a problem can only occur in the absence of processor power, which is typical for certain MYSTERY models. 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 bridge of the rectifier of the mains voltage and the power switch (s) of the converter.
It should be borne in mind that in the practice of repair it is extremely rare that key transistors in switching power supplies (SMPS) fail for no reason that should be sought by checking other components, for example, a breakdown of the key can provoke faulty elements of the damper circuits, or dried electrolytic capacitors or dangling primary resistors BP circuits involved in the stabilization process. In this case, all semiconductor elements of the strapping of the PWM controller chip are subject to verification, which it is desirable to verify by replacement.
Sometimes the MYSTERY MTV-1918LW 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 for the backlight LEDs of the V185B1-L17 panel, or a break in the LED circuit is possible. In such cases, first of all, it is necessary to verify the serviceability of all the electrolytic capacitors of the filter by supplying the LED driver itself, including in the power supply unit (power supply unit).
In most cases of lack of backlight, it becomes necessary to disassemble the panel in order to check the LEDs, connectors, loops and all contact connections. If one or several LEDs does not work in one line, therefore, they are broken and should be replaced.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes.
The motherboard MSTV2407-ZC01-01 must be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or lights up continuously. In such cases, if the converters or power regulators of the microcircuit are working, a software update may be necessary.
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 FLASH chips: GD25Q32 and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
If the TV works normally from external devices, but does not tune into television channels, the tuner F35WT-2A-E may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals, as well as the power supply of varicaps (30-33V).
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair only to professionals with sufficient experience in the field of electronic equipment repair.


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    MSTV2407-ZC01-01 
.......also Applies to TVs models BBK LEM2681F, BBK LEM2682, BBK LEM2284F..........

FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-1918LW Ver: V2N01 Main: MSTV2409-ZC01-01), TSUMV59XUS, Spi Flash: MX25L3205D


 In case of failures in Winbond's SPI FLASH software, we recommend that you replace the chip itself with a new one. Sometimes Winbond microcircuits can recover for some time after high-temperature exposure, for example, heating with a soldering station or a lighter, which is sometimes enough to read its contents.
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.C1), BBK LEM3284F (Panel HV320WXC-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), MYSTERY MTV-3018LW (Panel V290BJ1-PE1), MYSTERY MTV-1911LW (Panel HT185WX7-100), MYSTERY MTV-1922LW (Panel V185B1-L17), MYSTERY MTV-1913LW (Panel HT185WX7-100), MYSTERY MTV-3218LW (Panel HV320WX2-20A), MYSTERY MTV-1918LW (Panel V185B1-L17), MYSTERY MTV-2213LW (Panel M215HGE-L10), MYSTERY MTV-2222LW (Panel M215HG-LE4 REV.C3), MYSTERY MTV-2418LW (Panel HM236WUA-100), MYSTERY MTV-2424LW (Panel HM236WU8-100), MYSTERY MTV-1914LW (Panel V185B1-L15 Rev.c1), MYSTERY MTV-3223LW (Panel LK315T3HB94), MYSTERY MTV-2422LW (Panel HM236WU8–100), MYSTERY MTV-3224LW (Panel T320XVN09.0), MYSTERY MTV-2218LW (Panel CLAA215FA10), MYSTERY MTV-1911WL (Panel V185B1-L15 REV.C1), MYSTERY MTV-3221LW (Panel HV320WX2-268), MYSTERY MTV-2211W (Panel M215HG-LE4 ).
Main features of the MYSTERY MTV-1918LW device:
Installed matrix (LED-panel) V185B1-L17 or V185B1-PE1.
The matrix control uses the Timing Controller (T-CON) M185B3-L01-X + C.
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 chips: MST6E182VG-LF-Z1, FLASH: GD25Q32, Sound: TDA1517 and others.
The F35WT-2A-E tuner provides television reception and channel tuning.
Information from an alternative source:
MYSTERY MTV-1918LW Version V3M02
Panel Type (Matrix): V185B1-L17
Motherboard: MSTV2407-ZC01-01, GD25Q32, Tuner: F35WT-2A-E,