Thursday, 30 April 2020

REPAIR / SERVICING TV MYSTERY MTV-3224LT2

Technical description and composition of the MYSTERY MTV-3224LT2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-3224LT2
Chassis / Version: MSDV3222-ZC01-01
Panel: HV320WX2-20A
LED driver (backlight): integrated into MainBoard
PWM LED driver: AP3039AM-G1, AP3608EM-G1
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: MSDV3222-ZC01-01
IC MainBoard: CPU: MSD308BT-SW, SPI Flash: 25L64; Scaler: NT71263FG-300; EEPROM: 24C16;
Technical Specifications MTV-3224LT2
MYSTERY MTV-3224LT2
General repair guidelines for TV LCD LED
Repair of the MYSTERY MTV-3224LT2 TV should begin with a careful external examination of all its components and modules. 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. Experienced repairmen are well aware of how ring cracks in soldered terminals look, swollen capacitors, and other causes of problems in electronic devices.
Sometimes the MYSTERY MTV-3224LT2 TV simply does not turn on. No control lights on the front panel are lit or blinking, the TV does not respond to the remote control and does not make any sounds or any signs of life when turned on. The most likely cause of the malfunction is a failure of the common power module. If it is working properly, you must check the standby batteries on the Main Board. 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.
As a rule, the keys in switching power supplies (SMPS) are reliable enough and rarely fail for no reason to be looked for by checking other components of the circuit - electrolytic capacitors, resistors and semiconductor elements of the primary circuit. The PWM chip is verified by replacing it with a known good one.
If the MYSTERY MTV-3224LT2 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 HV320WX2-20A 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.
Often there is a need for disassembling the panel to check the health of the LEDs, as well as contact connections in the connectors and soldering.
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.
If the motherboard MSDV3222-ZC01-01 is faulty, first of all it is necessary to check all the linear stabilizers and power converters of its chips, as well as, if necessary, update the software (software). Sometimes you can check the health of MB only by replacement.
In cases of attempts to repair the MB board (SSB), it is necessary to check the health of its elements - CPU: MSD308BT-SW, SPI Flash: 25L64; Scaler: NT71263FG-300; EEPROM: 24C16; 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).
Remember! Attempts to self-repair by users of the MYSTERY MTV-3224LT2 TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!


FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-3224LT2, Main: MSDV3222-ZC01-01, Panel: HV320WX2-20A

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-3224LT2 device:
Installed matrix (LED-panel) HV320WX2-20A.
To power the backlight LEDs, a converter is used, combined with the main board MSDV3222-ZC01-01, controlled by the AP3039AM-G1, 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 PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is an MSDV3222-ZC01-01 module, using CPU chips: MSD308BT-SW, SPI Flash: 25L64; Scaler: NT71263FG-300; EEPROM: 24C16; and others.
The MYSTERY MTV-3224LT2 TV with an HV320WX2-20A LCD display, 32 "(81 cm) diagonal size is 16: 9. The LED panel of this TV has LED backlighting - Edge LED. You can view images in high quality HD with Resolution 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: MP3, JPEG.
The power of the sound system 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, 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: 800x600, 1024x768, 1360x768.
A digital tuner is capable of receiving television channels in the DVB-T, DVB-C, DVB-T2 standards.
Dimensions: With stand 642x444x209 mm, Without stand 570x345x70 mm.
Attention! The HV320WX2-20A panel of the MYSTERY MTV-3224LT2 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.