Friday, 31 July 2020

REPAIRING / SERVICING TV SUPRA STV-LC32ST2000W

Technical description and composition of the SUPRA STV-LC32ST2000W TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC32ST2000W
Chassis / Version: CV338H-T42
Panel: HK315LEDM-JH36H
LED driver (backlight): integrated into MainBoard
PWM LED driver: BIT3267
MOSFET LED driver: AOD4454
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: CV338H-T42
IC MainBoard: MSD6A338, MSB102KT, W25Q16DVSSIG, THGBM8G5D1KBAIL
Tuner: CDT-9NT372RF-10 (R842)
STV-LC32ST2000W Specifications
SUPRA STV-LC32ST2000W
General recommendations for TV LCD LED repair
Possible malfunctions
- TV SUPRA STV-LC32ST2000W does not turn on and does not give any signs of turning on, does not respond to control buttons and to the remote control.
In such cases, the AC / DC converter of the mains voltage, which is combined with the CV338H-T42 main board, is often faulty. Its output voltages should be measured and, in their absence, the power switches and rectifier diodes should be checked for the probability of a short circuit in the converters.
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 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 regulators (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
Often in such cases there is no backlighting 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 blinks or is on constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the CV338H-T42 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). In cases of attempts to repair the MB (SSB) board, it is necessary to check the serviceability of its elements - MSD6A338, MSB102KT, W25Q16DVSSIG, THGBM8G5D1KBAIL which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its pins with the board (indicated by warming up).
If there is no reception of television channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the CDT-9NT372RF-10 (R842) tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.
Owners of the STV-LC32ST2000W 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!


DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   --------->   Chassis CV338H-T42-13B


 The appearance of the MainBoard CV338H-T42 is shown in the figure below:
CV338H-T42
CV338H-T42 can be used in TVs:
BBK 32LEX-5023/T2C (Panel V320BJ6-Q01 Rev.C1 (TH32YS1705C0327)), BBK 32LEX-5024/T2C (Panel TH32YS1704D0089).
Main features of SUPRA STV-LC32ST2000W device:
Installed matrix (LED panel) HK315LEDM-JH36H.
To power the backlight LEDs, a converter combined with the CV338H-T42 main board is used, controlled by the BIT3267 PWM controller. The keys of the AOD4454 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 PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a CV338H-T42 module, using MSD6A338, MSB102KT, W25Q16DVSSIG, THGBM8G5D1KBAIL and others.
Tuner CDT-9NT372RF-10 (R842) provides reception of television programs and tuning to channels.
SUPRA LED TV STV-LC32ST2000W with LCD HK315LEDM-JH36H, 32 "(81 cm) 16: 9. operation of LEDs depending on the illumination of areas in the scene.The technology of manufacturing the display model uses LED LED backlighting.It is possible to view programs and films and images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready).
STV-LC32ST2000W has built-in SMART software and pre-installed Android operating system. Internet connection can be made via Wi-Fi wireless connection. 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.
An external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, VGA, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi. A headphone output is provided. The digital tuner is capable of receiving TV channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Attention! The HK315LEDM-JH36H panel of the SUPRA STV-LC32ST2000W 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.