Wednesday 5 August 2020

REPAIRING / SERVICING TV SUPRA STV-LC29270WL

Technical description and composition of the SUPRA STV-LC29270WL TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC29270WL
Chassis / Version: V1L11
Panel: V290BJ1-PE1 V Rev.C2 SEL290E1 S00B (11) Rev.R1
LED driver (backlight): integrated into PSU
PWM LED driver: OB8362HP
MOSFET LED driver: ME15N10-G
Power Supply (PSU): 168P-P29EWB-W0
PWM Power: OB2273D
MOSFET Power: 7N65
MainBoard: 5800-A8M280-0P10
IC MainBoard: CPU: MST6E182VG-LF-Z1, SPI Flash: EN25Q32B, Audio: YD1517
Tuner: ET-9Z2E-CF106H
STV-LC29270WL Specifications
SUPRA STV-LC29270WL
General recommendations for TV LCD LED repair
Possible manifestations of defects
- The SUPRA STV-LC29270WL TV does not turn on and does not show any signs of operation at all. No response to the remote control and front panel control buttons.
In such cases, the power supply 168P-P29EWB-W0 usually fails. It is necessary to measure its output supply voltages, and in their absence, check the serviceability of the power switches (7N65) of the converters and rectifier diodes for the probability of breakdown in semiconductor PN junctions.
In the event of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor in the source of the key usually breaks 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) OB2273D are usually checked by replacing them with new ones, or knowingly working.
- There is no image, the screen is black, there is sound, when the screen is illuminated outside, you can sometimes see barely noticeable outlines of the image.
A malfunction is usually in these cases most likely in the backlight units of the display matrix. Usually the cause of the malfunction is in the breakage of the LEDs, or in the connectors of the LED strips, but sometimes the LED driver is also faulty.
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 TV does not go into operation, does not respond to the remote control. The indicator on the front panel is on or blinking.
Repair or diagnostics of the 5800-A8M280-0P10 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 the chips - CPU: MST6E182VG-LF-Z1, SPI Flash: Q32B-104HIP, Audio: YD1517 with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.
If there is no tuning for terrestrial or cable TV channels, you should make sure that the software is correct, as well as that the supply voltages on the terminals of the ET-9Z2E-CF106H tuner match. It is also necessary to check with an oscilloscope the presence of pulses of data exchange between the tuner and the processor via the I2C bus.
Owners of the STV-LC29270WL 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 FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC29270WL V1L11, Main: 5800-A8M280-0P10, Panel: V290BJ1-PE1 V Rev.C2 SEL290E1 S00B (11) Rev.R1 

DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    168P-P29EWB-00 Power supply


 LED current in the panel = 476 mA, in order to reduce the backlight current, you need to increase the value of the resistors connected between pin 14 of OB8362HP and the case.
47k + 62 = 26.6k current = 476 mA.
47k + 68 = 27.7k current = 455 mA.
47k + 82 = 29.7k current = 423 mA.

https://3.bp.blogspot.com/-O5Kns6-Wtsw/XxL9AbNtpFI/AAAAAAABBmc/xGRZUcXS4HUPMtTMwCt_GCTJM4g_CwL1gCK4BGAYYCw/s1600/5800-A8M280-0P10_DCE.jpg

Additional MainBoard Repair
The MainBoard 5800-A8M280-0P10 is shown in the figure below:
5800-A8M280-0P10
5800-A8M280-0P10 can be used in TVs:
AIWA 32LE6110 (Panel T320HVN01.V2), AIWA 24LE6110 (Panel V236H1-LE4 Rev.C1), HYUNDAI H-LED29V17 (Panel V290BJ1-PE1 VRev.C2), SUPRA STV-LC24660FL (Panel HM236WU3-100), SUPRA STV-LC19660WL (Panel E185SG01), SUPRA STV-LC19663WL (Panel E185SG02).
External view of the power supply
Main features of SUPRA STV-LC29270WL device:
Installed matrix (LED-panel) V290BJ1-PE1 V Rev.C2 SEL290E1 S00B (11) Rev.R1.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by the OB8362HP PWM controller. The keys of the ME15N10-G type are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the SUPRA STV-LC29270WL TV is carried out by the 168P-P29EWB-W0 power module, or its analogs using OB2273D microcircuits and 7N65 power switches.
MainBoard - the main board (motherboard) is a 5800-A8M280-0P10 module, using CPU chips: MST6E182VG-LF-Z1, SPI Flash: EN25Q32B, Audio: YD1517 and others.
Tuner ET-9Z2E-CF106H provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V290BJ1-PE1
Type: a-Si TFT-LCD, CELL
Diagonal size: 29.0 inch
Resolution: 1366x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 631.092x354.816 mm
Surface: Antiglare (Haze 1%)
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 5.4% (with Polarizer)
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit)
Response Time: 9.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
LED TV SUPRA STV-LC29270WL with LCD display, diagonal size 29 "(74 cm) 16: 9 format. The required brightness of the screen of 300 cd / m2 is provided by LED backlight. 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 and films and images in high quality HD at a resolution of 1366x768 pixels in a graphic resolution of 720p (HD Ready). 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, 1080p standards 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, component, VGA, HDMI, 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.
Overall dimensions: 665x466x196 mm.
TV weight: 5.8 kg.
Attention! SUPRA STV-LC29270WL LED TV panel 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.