Friday 31 July 2020

REPAIRING / SERVICING TV SUPRA STV-LC32T420WL

Technical description and composition of the SUPRA STV-LC32T420WL TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC32T420WL
Chassis / Version: V1N10
Panel: LVW320CSOT E155 V2
LED driver (backlight): integrated into MainBoard
PWM LED driver: MP3398A
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6 (RT7738F)
MainBoard: 40-MT31BP-MAA2LG
IC MainBoard: CPU: MT5531NDNT; SPI Flash: 25Q64F; SOUND: RT9108NB
Tuner: 07-600C13-SA2G ST34WN-2T-E
STV-LC32T420WL Specifications
SUPRA STV-LC32T420WL
General recommendations for TV LCD LED repair
Repair and diagnostics of any electronic device, in particular SUPRA STV-LC32T420WL, it is advisable to begin with a careful external examination of the internal and external elements. Often, based on external signs and the nature of damage to elements, it becomes possible to draw some conclusions and determine a further algorithm for searching for a defect before taking the necessary measurements at control points. Swollen electrolytic or sintered capacitors, charred resistors, ring cracks in the soldering of the element terminals - all this can significantly help the master to determine the causes and consequences of the malfunctions in the TV.
In the absence of any signs of operability, when SUPRA STV-LC32T420WL does not turn on and does not signal anything with indicator lamps on the panel, there is a possibility of a malfunction of the TV power module. The power regulator of the control processor on the motherboard may also be faulty with the same manifestations. In general, first of all, it is necessary to check the electrolytic capacitors of the filters of the secondary rectifiers and the fuse at the mains input. If it is cut off, then the diodes of the rectifier bridge and the key transistor of the converter, which can be located either on a separate radiator or integrated with a PWM controller into a common microcircuit, should be checked for PN-transition breakdown. Options are possible.
In most cases, breakdowns of keys in switching power supplies (SMPS) do not occur without reason and you should look for other faulty circuit elements that could provoke a defect. This can be dry electrolytic capacitors in the primary circuit, and faulty damper elements, as well as broken resistors or punctured semiconductor elements in the stabilization circuits. Possible defect of the PWM chip from the manufacturer.
If SUPRA STV-LC32T420WL has no image, but there is sound, there may be a malfunction of the LVW320CSOT E155 V2 panel backlight LEDs or their power converter. You should also make sure that the electrolytic capacitors of the secondary rectifiers of the common power supply are in good working order.
It is often necessary to disassemble the panel to check the health of the LEDs, as well as the contact connections in the connectors and solders.
When diagnosing, it must be borne in mind that it is impossible to check for an open in the circuit of the LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally a current source.
On the 40-MT31BP-MAA2LG motherboard, in the event of a malfunction, you should first check the operability of all stabilizers or power converters of microcircuits and, if necessary, update the software (software).
When repairing an MB board, you need to check its components SPI Flash: 25Q64F. Defective elements must be replaced. If BGA chips are installed, their failure is usually localized by warming up.
If the TV operates normally from external devices, but does not tune to TV channels, the 07-600C13-SA2G ST34WN-2T-E tuner may be faulty. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals.
Attention to the owners! Attempts to repair the SUPRA STV-LC32T420WL TV yourself are not recommended by the manufacturer and can lead to serious negative consequences!


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC32T420WL V1N10, Main: 40-MT31BP-MAA2LG, Panel: LVW320CSOT E155 V2


https://2.bp.blogspot.com/-ejN2xTiNSVU/XyPbplUyOzI/AAAAAAABCcY/EK-rt63MkYoAVA_q23xBYF6cB3smjAIDwCK4BGAYYCw/s1600/40-MT31BP-MAA2LG_DCE.jpg The appearance of the MainBoard 40-MT31BP-MAA2LG is shown in the figure below:
40-MT31BP-MAA2LG
40-MT31BP-MAA2LG can be used in TVs:
ERISSON 32LET82 (Panel LVW320CSOT E145 V2), ERISSON 32LET42T2 (Panel LVW320CSOT E274 V2), ERISSON 32LET41T2 (Panel LVW320CS0T E274 V2), FUSION FLTV-32T21 (Panel LVW320CZOT), SUPRA STV-LC32T420WL (Panel LVW320CSOT E155 V2), SUPRA STV-LC32T850WL (Panel LVW320CSOT E45 V1), SUPRA STV-LC28T662WL (Panel T8-28T3520-LPM20), SUPRA STV-LC24T850WL (Panel 720p HD 1366x768), TELEFUNKEN TF-LED32S29T2 (Panel LVW320CS0T E198 V4), TELEFUNKEN TF-LED24S29T2 (Panel V236BJ1-LE2 Rev.C1), THOMSON T24E12DHU-01B T24E12DHU (Panel LVW240AUDX E2 V6).
Main features of SUPRA STV-LC32T420WL device:
Installed matrix (LED panel) LVW320CSOT E155 V2.
To power the backlight LEDs, a converter combined with the 40-MT31BP-MAA2LG main board is used, controlled by the MP3398A PWM controller.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using PWM SOT23-6 (RT7738F) microcircuits.
MainBoard - the main board (motherboard) is a 40-MT31BP-MAA2LG module, using CPU chips: MT5531NDNT; SPI Flash: 25Q64F; SOUND: RT9108NB and others.
Tuner 07-600C13-SA2G ST34WN-2T-E provides reception of TV programs and tuning to channels.
LED TV SUPRA STV-LC32T420WL with LCD LVW320CSOT, 32 "(81 cm) 16: 9. 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 a graphic resolution of 720p (HD Ready). high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC Graphic processing and digital signal shaping occurs in 480i, 480p, 576i, 576p, 720p, 1080i standards Supported media file formats: MP3, JPEG.
Speaker power of 10 W (2x5 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, audio x2, component, VGA, HDMI x2, USB. 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 735x481x160 mm, Without stand 735x432x83 mm.
Attention! The panel LVW320CSOT E155 V2 of the SUPRA STV-LC32T420WL 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.