Technical description and composition of the MYSTERY MTV-770 TV, type of panel and applicable modules. The composition of the modules.MYSTERY
Model: MTV-770
Chassis / Version: V2L10
Panel: HSD-7A
MainBoard: MP5-TV V3.0
IC MainBoard: Flash: 25LD51, EEPROM: 24C32P, SOUND: A6019
Tuner: XF-6AS (TDQ)
Appearance
MYSTERY MTV-770
General recommendations for repairing TV LCD
Repair of all electronic devices, including the MYSTERY TV, made on the basis of the V2L10 chassis, it is advisable to start with an external examination of its external and internal elements. Often, by the external signs and nature of the damage to the elements, it becomes possible to draw some conclusions and determine a further algorithm for finding a defect before making the necessary measurements at control points. Elements with visible damage, for example, capacitors swelled up after boiling the electrolyte, charred resistors in certain nodes of the circuit, as well as ring cracks in solders will help the master to guess the causes and possible consequences of the malfunction.
In the absence of any signs of operability, when the MYSTERY MTV-770 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. In the absence of swollen filter capacitors of the secondary rectifiers, the diagnostics of the power supply should be started by checking the fuse and, if it is broken, it is first necessary to check all the power semiconductor elements of the primary circuit - diodes and transistors for the possibility of an avalanche or thermal 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.
In those cases when the MYSTERY MTV-770 TV has lost an image, and the sound is there and all other functions are operational, there is a possibility of an inverter (converter for powering the backlight) malfunction. When you turn on the TV, the image may appear briefly and immediately disappear. It must be borne in mind that with such manifestations, the lamps themselves also fail, the malfunction of which can be detected by replacement, by connecting to the connectors for diagnostics that are known to be serviceable and suitable in power. It should be remembered that when protection is disabled in order to diagnose a malfunction, there is always a risk of failure of the power elements of the inverter. After repair, it is necessary to restore all standard converter protection circuits.
On the MP5-TV V3.0 motherboard, in the event of a malfunction, you should first check the performance of all the stabilizers or power converters of the microcircuits and, if necessary, update the software (software). In some cases, to repair the MB board (SSB), it may be necessary to replace the chips - Flash: 25LD51, EEPROM: 24C32P, SOUND: A6019 with new or obviously working ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
Once again, remind users! Attempts to self-repair a TV MYSTERY MTV-770 without the appropriate qualifications and experience can lead to its complete non-repairability!
FIRMWARE FOR SPI FLASH -----------> MYSTERY MTV-770 (V2L10), Main MP5-TV V3.0, Panel HSD-7A
The appearance of the MainBoard MP5-TV is shown in the figure below:MP5-TV
Main features of the MYSTERY MTV-770 device:
Installed matrix (LCD panel) HSD-7A.
The required supply voltage for all nodes of the TV MYSTERY MTV-770 provides a switching power supply.
MainBoard - the main board (motherboard) is an MP5-TV module using Flash chips: 25LD51, EEPROM: 24C32P, SOUND: A6019 and others.
The XF-6AS (TDQ) tuner provides TV reception and channel tuning.