REPAIRING AND NOT THROWING AWAY

REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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Wednesday 29 April 2020

REPAIR / SERVICING TV MYSTERY MTV-2231LT2

Technical description and composition of the MYSTERY MTV-2231LT2 TV, type of panel and applicable modules. The composition of the modules.
MYSTERY LED
Model: MTV-2231LT2
Chassis / Version: V2P05
Panel: LC215DT4A
LED driver (backlight): integrated into MainBoard
PWM LED driver: AP3064, OB3350
MOSFET LED driver: MDD1951
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MOSFET Power: SMK0870F
MainBoard: MS308C1-ZC01-01
IC MainBoard: CPU: MSD308BEM, SPI Flash: GD25Q64, AUDIO: TPA1517
Tuner: TDA18275
Technical Specifications MTV-2231LT2
MYSTERY MTV-2231LT2
General repair guidelines for TV LCD LED
Possible malfunctions
- MYSTERY MTV-2231LT2 does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
The malfunction in such cases, first of all, should be sought in the power elements of a switching power supply (IIP) - a network voltage converter (AC / DC), which in this TV model is combined with the MainBoard MS308C1-ZC01-01 main board. It is necessary to measure its output supply voltage, and in case of their absence, check the serviceability of the power switches (SMK0870F) of the converters and rectifier diodes for the probability of breakdown in PN semiconductor junctions.
In the event of breakdowns in the secondary circuits of the converter, it can usually fail in short circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse or current sensor at the source of the key most often breaks.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM SOT23-6 PWM controllers, in the absence of visible damage or obvious short-circuit between the terminals, are checked by replacing with new ones, or obviously working.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
As a rule, in such cases there is no display backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the line of series-connected LEDs without a special current source, and for this purpose it is not safe to use any voltage sources above 12V for them. Then it remains only to open the panel and check each LED separately. Usually, Chinese 9V-powered multimeters light up a single 3-volt LED, if you connect the probes in the forward direction, the red probe to the anode, and the black to the cathode. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the motherboard MS308C1-ZC01-01 should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). In some cases, to repair the MB board (SSB), it may be necessary to replace the chips - CPU: MSD308BEM, SPI Flash: GD25Q64, AUDIO: TPA1517 with new or obviously good ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
Before replacing the TDA18275 tuner, if there is no tuning to the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Once again, remind users! Attempts to independently repair the MYSTERY MTV-2231LT2 TV without the appropriate qualifications and necessary experience can lead to its complete non-repairability!
FIRMWARE FOR SPI FLASH  ----------->   MYSTERY MTV-2231LT2 V2P05, Main: MS308C1-ZC01-01, Panel: LC215DT4A


 To reduce the backlight current in LED drivers with the AP3064 controller (AP3064AM), it is necessary to proportionally increase the resistance of the resistor from pin 2 (ISET) to the housing. The maximum current in each of the four channels (in milliamperes) for the Rset resistor (in kilo-ohms) is determined from the ratio 1200 / Rset.
Repair MainBoard
The appearance of the MainBoard MS308C1-ZC01-01 is shown in the figure below:
MS308C1-ZC01-01
MS308C1-ZC01-01 can be used in TVs:
Haier LE32B8000T (Panel LSC320AN02-S01), JVC LT-32M340 (Panel LK315T3HB87 ), MYSTERY MTV-3230LT2 (Panel V320BJ7-PE1), MYSTERY MTV-2426LT2 (Panel V236BJ1-P03), MYSTERY MTV-2231LT2 (Panel LC215DT4A).
Main features of the MYSTERY MTV-2231LT2 device:
Installed matrix (LED panel) LC215DT4A.
To power the backlight LEDs, a converter is used, combined with the main board MS308C1-ZC01-01, controlled by the AP3064, OB3350 PWM controller. As the power elements of the LED driver, keys of the MDD1951 type are used.
The power module is combined with the MainBoard and is designed according to the flyback AC / DC voltage converter using PWM SOT23-6 microcircuits and power switches of the SMK0870F type.
MainBoard - the main board (motherboard) is an MS308C1-ZC01-01 module, using CPU chips: MSD308BEM, SPI Flash: GD25Q64, AUDIO: TPA1517 and others.
The TDA18275 tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: PANDA
Model: LC215DT4A
Type: a-Si TFT-LCD, CELL
Diagonal size: 21.5 inch
Resolution: 1920x1080, FHD
Display Mode: TN, Normally White, Transmissive
Active Area: 476.64x268.11 mm
Surface: Antiglare, Hard coating (3H)
Glass Depth: 0.70 + 0.70 mm
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit)
Response Time: 5 (Tr + Td)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V
MYSTERY MTV-2231LT2 TV with LC215DT4A LCD, diagonal size 22 "(56 cm), 16: 9 format. The required screen brightness of 200 cd / m² is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 1000: 1. The LED screen technology is implemented in the manufacturing technology of the screen of this TV model.The design and technical capabilities of the TV include watching programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphical decomposition according to the standard 1080p (Full HD). the input high-frequency or video signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, MKV, 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: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
The power consumed by the TV in the operating mode from the network is 38 watts.
Overall dimensions: 520x360x160 mm.
Mass of the TV: 3 kg.
Attention! The LC215DT4A panel of the MYSTERY MTV-2231LT2 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.
Posted By: FRANK at 04:03
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