Technical description and composition of the SUPRA STV-LC40T420FL TV, panel type and modules used. The composition of the modules.SUPRA LED
Model: STV-LC40T420FL
Chassis / Version: V1N10
Panel: LVF400CMOT E7 V4
LED driver (backlight): integrated into PSU
PWM LED driver: MP3394
MOSFET LED driver: AOD458 (14A / 250V), SM1110NS
Power Supply (PSU): IPE06R41
PWM Power: TEA1733, MC34063
MOSFET Power: 7N65, AOD4185
MainBoard: MT31LB 40-T31TOT-MAD2HG
IC MainBoard: TPA3110D2, W25Q64FVSIG, ATBM7811B
Tuner: RE221ZN V4A07AA
STV-LC40T420FL Specifications
SUPRA STV-LC40T420FL
General recommendations for TV LCD LED repair
Possible manifestations of defects
- SUPRA STV-LC40T420FL TV does not turn on, does not respond to the remote control and control panel buttons, does not flash any indicators.
In such cases, the IPE06R41 power supply usually fails. It is necessary to measure the secondary output supply voltages, and in their absence, check the serviceability of the power switches (7N65, AOD4185) of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in short-circuit mode, and in case of short-circuit in the elements of the primary circuit, the mains fuse usually breaks.
Breakdown of Mos-Fet switches used in switching power supplies is often caused by malfunctions of other elements, for example, supply, frequency setting, damper ... as well as elements of Negative Feedback of stabilization. The PWM microcircuit (PWM) TEA1733, MC34063 can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, there is sound, it reacts to the remote control. Or, immediately after switching on for a second, the image may appear and immediately disappear.
Often in such cases there is no backlighting of the LED panel. 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.
It is impossible to check the LED bars for a break without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters tend to light a single 3V LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as an indicator of serviceability. In faulty LEDs, the zener diode will either be cut off, or pierced in the K / Z.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the MT31LB motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Often the MB (SSB) board needs to be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - TPA3110D2, W25Q64FVSIG, ATBM7811B and replace the failed chips with new ones. Some malfunctions may be associated with the use of BGA soldering technologies in modern Main Board. Typically, such defects are detected by local heating of the chip.
If there is no reception of TV channels, but the TV is working properly from external devices, first of all, you need to check the power supply voltage of the RE221ZN V4A07AA tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.
Attention to TV owners! Attempts to repair SUPRA STV-LC40T420FL yourself are not recommended by the manufacturer and can lead to serious negative consequences!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL psu ------------------> IPE06R41
To reduce the backlight current in LED drivers with an MP3394S (MP3394) controller, increase the resistance of the resistor from pin 6 (ISET) to the case. The maximum current in each channel (in milliamperes) for the resistor Rset (in kilo-ohms) is determined from the ratio 790 * 1.23V / (Rset + 0.4).
Additional MainBoard RepairThe appearance of the MainBoard MT31LB is shown in the figure below:
MT31LB
External view of the power supply
Main features of SUPRA STV-LC40T420FL device:
Installed matrix (LED panel) LVF400CMOT E7 V4.
A converter combined with a power supply is used to power the backlight LEDs, and is controlled by the MP3394 PWM controller. The keys of the AOD458 (14A / 250V), SM1110NS type are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the SUPRA STV-LC40T420FL TV is carried out by the IPE06R41 power module, or its analogs using TEA1733, MC34063 microcircuits and power switches of the 7N65, AOD4185 type.
MainBoard - the main board (motherboard) is an MT31LB module, using TPA3110D2, W25Q64FVSIG, ATBM7811B and others.
Tuner RE221ZN V4A07AA provides reception of television programs and tuning to channels.
LED TV SUPRA STV-LC40T420FL with LCD LVF400CMOT, 39 "(99 cm) 16: 9. The required brightness of the screen of 300 cd / m² is provided by LED backlight. Dynamic contrast ratio of 100,000: 1 is achieved by special control of LED operation depending on the illumination of the areas in the scene.This model uses an LED-panel with an edge arrangement of backlighting LEDs - Edge LED.It is possible to view broadcasts, films and images in high quality HD at a resolution of 1366x768 pixels in the standard graphic resolution 720p (HD Ready). high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal formation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: MP3, JPEG.
Speaker power of 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, component, SCART, HDMI x3, USB x2. 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, 1360x768. The digital tuner is capable of receiving TV channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Dimensions: With stand 1235x758x284 mm, Without stand 713x435x86 mm.
Attention! The panel LVF400CMOT E7 V4 of the SUPRA STV-LC40T420FL LED TV 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.