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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Tuesday 28 July 2020

REPAIR / SERVICING TV SUPRA STV-LC4285FL

Technical description and composition of the SUPRA STV-LC4285FL TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC4285FL
Chassis / Version: V1J12 // V2K05
Panel: 42 inch Edge LED
T-CON: V420H2-CH1
LED driver (backlight): VDT70102.00 Rev: 3
Power Supply (PSU): 168P-P47TLK-20
PWM Power: STR-A6159M (Stb), SSC2001 (PFC), SSC9502S
MOSFET Power: MMBT3906Q4, 2SK3683
MainBoard: 5800-A8M890-0020 // 5800-A8M890-0030 & 5800-H8M680-1020
IC MainBoard: CPU: MSD306PT-LF, SPI FLASH: EN25B64
Tuner: XDTT-6F10 / W1146 // DTT-10B1C / GW12B5CU
Control: IR: 5800-R8M830-0000
STV-LC4285FL Specifications
SUPRA STV-LC4285FL
General recommendations for TV LCD LED repair
Possible manifestations of defects
- TV SUPRA STV-LC4285FL does not turn on and does not show any signs of operation at all. No response to the remote control and front panel control buttons.
In some of these cases, a fault is detected in the 168P-P47TLK-20 power supply module. It is necessary to measure the output voltages in its secondary circuits, and in the event of their complete absence, the serviceability of the power switches and rectifier diodes should be checked for a possible breakdown (short circuit).
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work in an emergency mode in a short-circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse often breaks.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly working properly.
- There is no picture, there is sound, it reacts to the remote control, the channels are switched. In some cases, the image appears when turned on and disappears immediately.
Most likely in these cases is a malfunction of the LED backlight. The reason may be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To check the health of the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED separately with a simple Chinese multimeter (powered by 9 volts) in the P-N transition test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black one to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. The serviceability of the PN junction of the Zener diode indirectly indicates the serviceability of the LED-a
- The TV does not go into operation, does not respond to the remote control. The indicator on the front panel is on or blinking.
Repair or diagnostics of the 5800-A8M890-0020 motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - SPI FLASH: EN25B64 with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.
Before changing the XDTT-6F10 / W1146 tuner, if it is not possible to tune to TV channels, you should make sure that there are supply voltages, which must be measured at the corresponding tuner terminals and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be monitored with an oscilloscope
Attention! Users and owners of STV-LC4285FL TVs who do not have the appropriate qualifications, knowledge and experience are strongly discouraged from trying to repair themselves in order to avoid negative consequences that can lead to the complete non-repairability of the device ..........


DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL  psu ------------>    168P-P47TLK-00 Power supply

 The appearance of the MainBoard 5800-A8M890-0020 is shown in the figure below:
5800-A8M890-0020
Main features of SUPRA STV-LC4285FL device:
Installed matrix (LED panel) 42 inch Edge LED.
Matrix control uses the Timing Controller (T-CON) V420H2-CH1.
The LED driver VDT70102.00 is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the SUPRA STV-LC4285FL TV is carried out by the 168P-P47TLK-20 power module, or its analogs using STR-A6159M (Stb), SSC2001 (PFC), SSC9502S microcircuits and MMBT3906Q4, 2SK3683 power switches.
MainBoard - the main board (motherboard) is a 5800-A8M890-0020 module, using CPU chips: MSD306PT-LF, SPI FLASH: EN25B64 and others.
Tuner XDTT-6F10 / W1146 // DTT-10B1C / GW12B5CU provides reception of television programs and tuning to channels.

LED TV SUPRA STV-LC4285FL with LCD 42, 42 "(107 cm) diagonal in 16: 9 format. The required screen brightness of 450 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum is 6000: 1. The display technology of the model uses LED backlighting. The capabilities of the TV provide viewing of broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC Graphic processing and digital signal shaping takes place in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p Supported media file formats: MP3, WMA, MPEG4, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV x2, audio x3, component, VGA, HDMI x3, USB. A headphone output is provided. To connect a computer or laptop to this TV model, use the VGA (D-Sub 15) connector on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768. The digital tuner is capable of receiving TV channels in DVB-T MPEG4 standards.
The power consumed by the TV in operating mode from the network is 120 watts.
Overall dimensions: 1090x750x255 mm.
TV weight: 20 kg.
Attention! The SUPRA STV-LC4285FL 42 inch Direct Led LED TV panel is an expensive and unreliable element.
Do not allow any impacts on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV non-repairable.