Technical description and composition of the TV SUPRA STV-LC1995WL, type of panel and applicable modules. The composition of the modules.SUPRA LED
Model: STV-LC1995WL
Chassis / Version: V1K03
Panel: LTM185AT04
T-CON: LTM185AT04S2L V0.6_HF (Fixed); LRX4211X0A, I7814HS, 416WP, A6168G
LED driver (backlight): KDL + L010E04-01
PWM LED driver: OZ9998AGN
Power Supply (PSU): L036C1-01 KPS
PWM Power: Q0465R
MainBoard: MST739 REV-00
IC MainBoard: MST739KE-LF, 3502M-G1, F80-100HCP, K24C64, K24C04, R2A15123FP, 4558CM-E1
Tuner: AFT7 / W119G
Technical Specifications STV-LC1995WL
SUPRA STV-LC1995WL
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The SUPRA STV-LC1995WL TV does not turn on. There are no signs of operability. The indicators on the front panel do not shine and do not blink, and the remote control and control buttons do not respond.
Failure in such cases should be sought in the power supply circuits L036C1. It is necessary to measure the secondary output supply voltages, and in case of their absence, check the operability of the power switches of the converters and rectifier diodes for the probability of breakdown in PN semiconductor junctions.
During thermal and avalanche breakdowns of semiconductors in secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And during short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch may be PWM Q0465R. It is checked only by replacement with a known good one.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
Failure in most such cases is detected in the nodes and backlight elements of the LED panel. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the circuit of the LED lines without disassembling the panels using a tester or a 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, each LED can be checked separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect probes in the forward direction to it. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as a health indicator. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the MST739 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - MST739KE-LF, 3502M-G1, F80-100HCP, K24C64, K24C04, R2A15123FP, 4558CM-E1 and replace the failed chips with new ones. Some malfunctions may be associated with the use of BGA soldering technologies in modern Main Board. Typically, such defects are detected by local heating of the chip.
If there is no reception of television channels, but the TV works properly from external devices, first of all you need to check the voltage of the AFT7 / W119G tuner and update the software. The pulses from the I2C bus must be monitored using an oscilloscope.
We recommend the owners of the STV-LC1995WL TV for repair only to qualified specialists with the necessary work experience! Attempts to repair it yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!
The appearance of the MainBoard MST739 is shown in the figure below:MST739
The appearance of the power supply
Main features of the SUPRA STV-LC1995WL device:
Installed matrix (LED-panel) LTM185AT04.
The matrix control uses the Timing Controller (T-CON) LTM185AT04S2L.
To power the backlight LEDs, the KDL + L010E04-01 LED driver is used, controlled by the OZ9998AGN PWM controller.
The necessary supply voltages are generated for all nodes of the SUPRA STV-LC1995WL TV by the power module L036C1, or its analogs using Q0465R microcircuits.
MainBoard - the main board (motherboard) is an MST739 module, using microcircuits MST739KE-LF, 3502M-G1, F80-100HCP, K24C64, K24C04, R2A15123FP, 4558CM-E1 and others.
The AFT7 / W119G tuner provides TV reception and channel tuning.
Information from an alternative source:
SUPRA STV-LC1995WL Model V1K03
Panel Type (Matrix): LTM185AT04,
Motherboard: MST739 REV-00, MST739KE-LF, 3502M-G1, F80-100HCP, K24C64, K24C04, R2A15123FP, 4558CM-E1, Tuner: AFT7 / W119G
T-con: LTM185AT04S2L V0.6_HF (Not removable), LRX4211X0A, I7814HS x2, 416WP, A6168G
Invertor: KDL + L010E04-01 P / N: * 35015533 REV00, OZ9998AGN,
PSU: KPS + L036C1-01 P / N: * 35014790, Q0465R CHASSIS MALFUNCTIONS BASED ON MST739
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTM185AT04-V
Type: a-Si TFT-LCD, Panel
Diagonal size: 18.5 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 409.8x230.4 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 72%
Response Time: 5 (Tr + Td)
Frequency: 60Hz
Lamp Type: 12S4P WLED Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V
LED TV SUPRA STV-LC1995WL with LCD display LTM185AT04, diagonal size 19 "(48 cm) 16: 9 format. The required brightness of the screen 300 cd / m² is provided by LED backlight LED. Contrast - the ratio of maximum brightness to minimum is 1000: 1. Dynamic contrast ratio of 50,000: 1 is achieved by special control of the LEDs depending on the illumination of areas in the plot.This model uses an LED panel with an end-face arrangement of the backlight LEDs - Edge LED. pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p.
The power of the sound system 4 W (2x2 W) provide two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV x2, audio x3, component, VGA, HDMI. An output for connecting headphones is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768, 1360x768.
The power consumed by the TV in the operating mode from the network is 32 watts.
Overall dimensions: With stand 474x350x210 mm, Without stand 474x313x35 mm.
Attention! The LTRA185AT04 panel of a SUPRA STV-LC1995WL LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.
