Tuesday, 28 April 2020

REPAIR / SERVICING TV MYSTERY MTV-1929LT2

Technical description and composition of the MYSTERY MTV-1929LT2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-1929LT2
Chassis / Version: MSDV3222-ZC01-01
Panel: V185BJ1-PE1 // HM185WX3-400; NT71263FG300
LED driver (backlight): integrated into Mainboard
PWM LED driver: AP3039AM-G1, AP3608EM
MOSFET LED driver: B6010D
Power Supply (PSU): integrated into Mainboard
PWM Power: PWM SOT23-6
MainBoard: MSDV3222-ZC01-01
IC MainBoard: SPI Flash: GD25Q64BV, DRAM: K4B1G1646G-BCKD, RT7257EN
Tuner: LHD
Technical Specifications MTV-1929LT2
MYSTERY MTV-1929LT2
General repair guidelines for TV LCD LED
Repair of TVs, as well as other devices, it is advisable to start with an external examination. Often, based on certain external signs, it may be possible to draw certain conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. Swollen electrolytic or cermet capacitors, charred resistors, ring cracks in the soldered terminals of the elements - all this can significantly help the master to determine the causes and consequences of the malfunction of the TV.
If the MYSTERY MTV-1929LT2 does not turn on, no control lights on the front panel light up or blink, therefore, there is a very high probability of a power module malfunction. In some cases, only the processor power regulator may be faulty. When diagnosing and repairing the power supply, first of all, replace the swollen filter capacitors 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.
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.
If there is no image when you turn on the MYSTERY MTV-1929LT2, or it appears and immediately disappears, but there is sound, most likely there is a malfunction in the backlight LED circuit of the V185BJ1-PE1 panel, or in their power converter.
To check the health of the LEDs and contact connections in their power circuit, the panel must be disassembled.
It should be remembered that it is not possible to determine the open circuit in the LED lines without disassembling the panels with a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required.
Repair of the motherboard MSDV3222-ZC01-01 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.
Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Check or replace elements of SPI Flash: GD25Q64BV; It requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can be diagnosed by warming up.

Once again, remind users! Attempts to self-repair a TV MYSTERY MTV-1929LT2 without the appropriate qualifications and experience can lead to its complete non-repairability!


FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-1929LT2, Main: MSDV3222-ZC01-01, Panel: V185BJ1-PE1

FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-1929LT2, Main: MSDV3222-ZC01-01, Panel: HM185WX3-400

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    MYSTERY MTV-3224LT2 Chassis MSDV3222-ZC01-01 (MSDV3222-YL01-01)



 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 MSDV3222-ZC01-01 is shown in the figure below:
The motherboard MSDV3222-ZC01-01 is made on a single chassis with a power module and an inverter to power the LED panel. The MSD308BT-SW multi-function control processor with built-in scaler is used. Repair of the power module is carried out according to standard technology - verification of power cells, electrolytic capacitors and secondary supply voltages. The following is a functional check of stabilizers and converters for powering the internal nodes of the processor and LCD panel. It should be borne in mind that if there are problems with the software in the SPI Flash chips manufactured by WINBOND, it is advisable to replace the chip itself with the contents of the software.
MSDV3222-ZC01-01 can be used in TVs:
BBK LEM3284DT2 (Panel LSC320AN02), MYSTERY MTV-2229LT2 (Panel M215HTN01.1 ), MYSTERY MTV-2429LT2 (Panel M240HTN01.2), MYSTERY MTV-2223LT2 (Panel LC215DTBA), MYSTERY MTV-2431LT2 (Panel V236BJ1 600), MYSTERY MTV-1924LT2 (Panel HT185WXF-100), MYSTERY MTV-3228LT2 (Panel LK315T3HB94), MYSTERY MTV-3023LT2 (Panel MT3151A05), MYSTERY MTV-2228LT2 (Panel RUNTK0001ZDP2), MYSTERY MTV-1929LT2 (Panel V185BJ1-PE1), MYSTERY MTV-3223LT2 (Panel LC315TU3A), MYSTERY MTV-3224LT2 (Panel HV320WX2-20A), MYSTERY MTV-3028LT2 (Panel ST2751A01-3), MYSTERY MTV-2428LT2 (Panel V236BJ1-P01), MYSTERY MTV-2424LT2 (Panel HM236WU8-200 ), MYSTERY MTV-4030LT2 (Panel V400HJ6-PE1), MYSTERY MTV-3031LT2 (Panel V290BJ1-PE1), MYSTERY MTV-3226LT2 (Panel V320BJ7-PE1).
Main features of the MYSTERY MTV-1929LT2 device:
Installed matrix (LED-panel) V185BJ1-PE1 or HM185WX3-400; NT71263FG300.
An integrated LED driver is used to power the backlight LEDs, it is controlled by the AP3039AM-G1, AP3608EM PWM controller. As power elements of the LED driver, keys of the type B6010D are used.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is an MSDV3222-ZC01-01 module, using SPI Flash chips: GD25Q64BV, DRAM: K4B1G1646G-BCKD, RT7257EN and others.
The LHD tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V185BJ1-PE1
Type: a-Si TFT-LCD, CELL
Diagonal size: 18.5 inch
Resolution: 1366x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 409.8x230.4 mm
Surface: Antiglare (Haze 1%)
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 5.0% (with Polarizer)
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit)
Response Time: 9.0 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V
MYSTERY MTV-1929LT2 TV with V185BJ1-PE1 LCD, 19 "(48 cm) diagonal size of 16: 9 format. The required screen brightness of 230 cd / m² is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 1000: 1. Edge LED backlighting is implemented 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 . Emah 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, DivX, JPEG.
The power of the sound system 10 W (2x5 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, 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, 1360x768, 1920x1080.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The V185BJ1-PE1 panel of the MYSTERY MTV-1929LT2 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!