Friday 31 July 2020

REPAIRING / SERVICING TV SUPRA STV-LC32T650WL

Technical description and composition of the SUPRA STV-LC32T650WL TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC32T650WL
Chassis / Version: V1R06
Panel: LC320DXJ-SFA2, RDL320HY (LD0-803) 45
LED backlight: 5800-W32001-3P02
LED driver (backlight): integrated into MainBoard
PWM LED driver: MP3398A
MOSFET LED driver: D4286
Power Supply (PSU): integrated into MainBoard
PWM Power: LNK6778K
MainBoard: 5800-A6M31G-0P10
IC MainBoard: SPI Flash: 25Q64CSIG, SOUND: TPA3113D2
Control: IR: 5800-RUE300-1P00
STV-LC32T650WL Specifications
SUPRA STV-LC32T650WL
General recommendations for TV LCD LED repair
Possible malfunctions
- SUPRA STV-LC32T650WL TV does not turn on, does not respond to the remote control and control panel buttons, does not light up or blink indicators.
A malfunction in such cases should be primarily looked for in the power elements of a switching power supply (SMPS) - a mains voltage converter (AC / DC), which in this TV model is combined with the MainBoard 5800-A6M31G-0P10 main board. It is necessary to measure its output voltages, and in case of their absence (full or partial), the serviceability of the power switches of the converters and rectifier diodes should be checked for a possible short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in an emergency mode of a short circuit, and with a short circuit in the power elements of the primary circuit, the mains fuse or current sensor in the source of the key is often cut off.
Breakdown of Mos-Fet switches used in switching power supplies is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM regulator, in frequency-setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) PWM SOT23-6 are usually checked by replacing them with new ones, or knowingly working.
- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and disappears immediately
A malfunction is usually in these cases most likely in the backlight units of the display matrix. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
To test the LED strips, to open all the transitions of the LEDs, you need several tens of volts or more, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in K / Z, then the LED is faulty and requires replacement.
- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the 5800-A6M31G-0P10 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 chips - SPI Flash: 25Q64CSIG, SOUND: TPA3113D2 with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.
Owners of the STV-LC32T650WL TV are advised to contact only qualified specialists with the necessary experience for repair! Attempts to repair yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!
To reduce the backlight current, you should proportionally increase the total resistance of the resistors relative to the case at the ISET pin of the MP3398A controller. ISET (Current Setting) - Pin 8 in SOIC-20 package or Pin 6 in SOIC-16 package.

 The appearance of the MainBoard 5800-A6M31G-0P10 is shown in the figure below:
5800-A6M31G-0P10
5800-A6M31G-0P10 can be used in TVs:
AIWA 32LE4020 (Panel LC320DXJ-SHA2 GDL320HY (LD0-008) Rev.00), AIWA 32LE7020 (Panel LC320DXJ (SH)(A2)), ERISSON 32LES71T2 (Panel LC320DXJ-SFA2), ERISSON 32LES70T2 (Panel LC320DXJ (SF)(A2)), SUPRA STV-LC32T650WL (Panel LC320DXJ-SFA2 RDL320HY(LD0-803)45).
Main features of SUPRA STV-LC32T650WL device:
Installed matrix (LED panel) LC320DXJ-SFA2, RDL320HY (LD0-803) 45.
To power the backlight LEDs, a converter combined with the 5800-A6M31G-0P10 main board is used, controlled by the MP3398A PWM controller. D4286 keys are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using LNK6778K microcircuits.
MainBoard - the main board (motherboard) is a 5800-A6M31G-0P10 module, using SPI Flash chips: 25Q64CSIG, SOUND: TPA3113D2 and others.
LED TV SUPRA STV-LC32T650WL with LCD display LC320DXJ-SFA2, 32 "(81 cm) diagonal, 16: 9 format. control of the LEDs depending on the illumination of areas in the scene. The display technology of the model uses LED LED backlight. It is possible to view broadcasts and films and images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). Input high-frequency or video signal decoded in analog systems PAL, SECAM, NTSC Graphic processing and digital signal shaping occurs in 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
Speaker power 12 W (2x6 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), SCART, HDMI x2, MHL, 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, 1360x768. The digital tuner is capable of receiving TV channels in the DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2 standards.
Dimensions: With stand 1235x758x284 mm, Without stand 713x435x86 mm.
Attention! Panel LC320DXJ-SFA2, RDL320HY (LD0-803) 45 SUPRA LED TV STV-LC32T650WL 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.