Wednesday 5 August 2020

REPAIRING / SERVICING TV SUPRA STV-LC32450WL

Technical description and composition of the SUPRA STV-LC32450WL TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC32450WL
Chassis / Version: V1P12
Panel: HK315LEDM-OHAJH
LED backlight: 032D900472 JS-MY24F JWD-0014 3BL-T6254102-21
T-CON: 3H5F5BEBS6 CV320PW05S
LED driver (backlight): integrated into MainBoard
PWM LED driver: SOIC8
MOSFET LED driver: TO-252
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MOSFET Power: TO-252
MainBoard: TP.VST59T.PB701
IC MainBoard: CPU: TSUMV59XET, SPI FLASH: GD25Q32CSIG, AUDIO: TPA3110LD2
Control: IR: 401-5C1C1-F4101 32C1 / K7
STV-LC32450WL Specifications
SUPRA STV-LC32450WL
General recommendations for TV LCD LED repair
Possible manifestations of defects
- SUPRA STV-LC32450WL does not turn on and does not show any signs of operability at all. Does not blink indicators and does not respond to control buttons.
In such cases, the AC / DC converter of the mains voltage, which is combined with the main board TP.VST59T.PB701, is often faulty. It is necessary to measure its output voltages, and if they are absent (full or partial), the serviceability of the power switches (TO-252) of the converters and rectifier diodes should be checked for a possible short circuit.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually operate in an emergency in the short-circuit mode, and in the event of a short-circuit in the power elements of the primary circuit, the mains fuse often breaks.
Breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM) PWM SOT23-6, if they have no visible damage to the case and an open short circuit between the pins, are usually checked by replacing.
- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and disappears immediately
Usually, in such cases, a malfunction is detected in the nodes of the backlight of the LED panel. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
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. By opening the panel, you can check each LED separately. Typically, Chinese multimeters light up one 3-volt LED slightly if the probes are connected to it in the forward direction. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or broken into 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 TP.VST59T.PB701 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). Complex repair of MB (SSB) board is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the CPU elements: TSUMV59XET, SPI FLASH: GD25Q32CSIG, AUDIO: TPA3110LD2. Malfunctions in BGA chips are usually easy to detect by warm-up.

Attention! Users and owners of STV-LC32450WL 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.
Additional MainBoard Repair
The appearance of the MainBoard TP.VST59T.PB701 is shown in the figure below:
TP.VST59T.PB701
Main features of SUPRA STV-LC32450WL device:
Installed matrix (LED panel) HK315LEDM-OHAJH.
Matrix control uses Timing Controller (T-CON) 3H5F5BEBS6.
To power the backlight LEDs, a converter combined with the main board TP.VST59T.PB701 is used, controlled by the SOIC8 PWM controller. TO-252 switches 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 PWM SOT23-6 microcircuits and TO-252 power switches.

The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using PWM SOT23-6 microcircuits and TO-252 power switches.
MainBoard - the main board (motherboard) is a TP.VST59T.PB701 module, using CPU chips: TSUMV59XET, SPI FLASH: GD25Q32CSIG, AUDIO: TPA3110LD2 and others.
SUPRA LED TV STV-LC32450WL with LCD HK315LEDM-OHAJH, 32 "(81 cm) 16: 9. operation of 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 is decoded in analog systems PAL, SECAM, NTSC Graphic processing and digital signal formation is performed in 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards Supported multimedia file formats: MP3, WMA, MPEG4, 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), AV, audio x2, component, VGA, HDMI x2, 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.
Dimensions: With stand 1235x758x284 mm, Without stand 713x435x86 mm.
Attention! The HK315LEDM-OHAJH panel of the SUPRA STV-LC32450WL 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.