Wednesday 5 August 2020

REPAIRING / SERVICING TV SUPRA STV-LC32550WL

Technical description and composition of the SUPRA STV-LC32550WL TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC32550WL
Chassis / Version: V1N03 // V1N07 soft V1.0.56
Panel: HV320WX2-201 // HV320WX2-209
T-CON: HV320WXC-200_X-PCB-X0.0
LED driver (backlight): integrated in Mainboard
PWM LED driver: OZ9902CGN
MOSFET LED driver: CS630 A4H
Power Supply (PSU): integrated in Mainboard
PWM Power: FAN6755
MOSFET Power: 7N65L
MainBoard: 35018209 KL32GT616-BOE-248TTK // 364YTK
IC MainBoard: FLASH Winbond: 25S32BVS1G, HDMI: IT6633E-P, Sound: STA333W
Tuner: TDA18273
STV-LC32550WL Specifications
SUPRA STV-LC32550WL
General recommendations for TV LCD LED repair
A faulty power supply is often trivial - the TV does not turn on, does not make any sounds, does not shine or blink with any indicators. When diagnosing and repairing the power supply, after replacing the swollen capacitors of the secondary rectifier filters (if any), you must first check the mains fuse. If it breaks, the power elements of the transistors and diodes of the rectifier bridge should be checked for avalanche (thermal) breakdown.
If a breakdown of the power switch is detected, it should be remembered that in a switching power supply (SMPS) it does not fail by itself without reasons that should be looked for by checking other elements of the primary circuit - electrolytic capacitors, PWM controller FAN6755, which can be checked only by replacement, as well as other semiconductor elements (diodes, transistors, zener diodes).
In cases where the SUPRA STV-LC32550WL TV has lost the image, but there is sound and all other functions are operational, there is a possibility of a malfunction of the LED driver (the converter for powering the backlight LEDs of the HV320WX2-201 panel). When you turn on the TV, the image may appear and disappear briefly. It should be borne in mind that with such manifestations, the LEDs themselves fail.
In most cases when there is no backlight, it becomes necessary to disassemble the panel in order to check the LEDs, connectors, loops and all contact connections. If one or more LEDs do not work in one line, therefore, they are punctured and should be replaced.
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
Repair of the motherboard 35018209 KL32GT616-BOE-248TTK must begin with diagnostics and testing of all linear stabilizers and power converters of its microcircuits. Sometimes it may be necessary to update the software (software) - flashing FLASH or EEPROM.
Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing FLASH elements Winbond: 25S32BVS1G, HDMI: IT6633E-P, Sound: STA333W requires the necessary training and professional skills to repair modules at the component level. Problems associated with BGA soldering technologies can be diagnosed by the warm-up method.
The malfunction of the TDA18273 tuner is established after checking the software and all supply voltages at its terminals. The I2C bus data exchange between the tuner and the processor can be monitored with an oscilloscope.
Attention to users! Self-repair of the SUPRA STV-LC32550WL TV without appropriate qualifications and experience can lead to its complete non-repairability!

DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC32550WL V1N03, Main: 35018209 KL32GT616-BOE-248TTK, Panel: HV320WX2-201

 The appearance of MainBoard 35018209 is shown in the figure below:
35018209
Main features of SUPRA STV-LC32550WL device:
Installed matrix (LED panel) HV320WX2-201 or HV320WX2-209.
Matrix control uses Timing Controller (T-CON) HV320WXC-200_X-PCB-X0.0.
An integrated LED driver is used to power the backlight LEDs, controlled by the OZ9902CGN PWM controller. The keys of the CS630 A4H type 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 FAN6755 microcircuits and 7N65L power switches.
MainBoard - the main board (motherboard) is a 35018209 module, using FLASH Winbond chips: 25S32BVS1G, HDMI: IT6633E-P, Sound: STA333W and others.
The TDA18273 tuner provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: BOE
Model: HV320WX2-201
Type: a-Si TFT-LCD, CELL
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: AFFS, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare (Haze 10%), Hard coating (3H)
Glass Depth: 0.70 + 0.70 mm
Transmissivity: 6.6% (with Polarizer)
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit)
Response Time: 8 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
SUPRA LED TV STV-LC32550WL with LCD HV320WX2-201, 32 "(81 cm) 16: 9. The required brightness of the screen of 400 cd / m² is provided by LED backlight. Dynamic contrast ratio of 80000: 1 is achieved by special control operation of LEDs depending on the illumination of areas in the scene.This model uses an LED-panel with an edge arrangement of backlight LEDs - Edge LED.It is possible to view broadcasts and films and images in high quality HD at a resolution of 1366x768 pixels in the standard graphic resolution 720p (HD Ready) The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC Graphic processing and digital signal shaping occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p Supported media file formats: MP3, MKV, 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 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, 1360x768.
Overall dimensions: 738x495x209 mm.
TV weight: 6.6 kg.
Attention! The HV320WX2-201 panel of the SUPRA STV-LC32550WL 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.