Thursday 23 April 2020

REPAIR / SERVICING TV SHIVAKI STV-24LED15

Technical description and composition of the TV SHIVAKI STV-24LED15, type of panel and applicable modules. The composition of the modules.
SHIVAKI LED
Model: STV-24LED15
Chassis / Version: TP.S512.PA63
Panel: HV236WHB-N00 M00
LED driver (backlight): integrated into MainBoard
PWM LED driver: SN51DP
MOSFET LED driver: PA1108DA
Power Supply (PSU): integrated into MainBoard
PWM Power: LD5530
MOSFET Power: N-FET TO-252
MainBoard: TP.S512.PA63
IC MainBoard: CPU: S2T512, SPI Flash: GD25Q64, Audio: YD1517P
Tuner: XF-3SDT-H + S2
Technical Specifications STV-24LED15W
SHIVAKI STV-24LED15
General repair guidelines for TV LCD LED
Possible malfunctions
- SHIVAKI STV-24LED15 does not turn on, does not respond to buttons and remote control, indicators on the front panel do not light up and do not blink.
The malfunction in such cases should be sought in the elements of the power source - the mains voltage converter (AC / DC), which is located on the MainBoard TP.S512.PA63 main board. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches (N-FET TO-252) and the rectifier diodes of the converters for a short circuit probability.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short-circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the main fuse and, less often, the current sensor at the source of the key are most often cut off.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM circuits LD5530 are usually checked by replacement with new, or obviously working.
- There is no image, but there is sound and all the other functions of the TV work. The image sometimes for a second appears immediately after turning on and disappears.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason can sometimes be in the power of the LEDs, but more often in their malfunction (breakdown or break), sometimes in the violation of the contact connections of the LED strips.
It is impossible to check the line of series-connected LEDs without a special current source, and for this purpose it is not safe to use any voltage sources above 12V for them. Then it remains only to open the panel and check each LED separately. Usually, Chinese 9V-powered multimeters light up a single 3-volt LED, if you connect the probes in the forward direction, the red probe to the anode, and the black to the cathode. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the TP.S512.PA63 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). If it is not possible to replace the MB (SSB) card, you need to check the health of its elements - CPU: S2T512, SPI Flash: GD25Q64, Audio: YD1517P. Defective components should be replaced.
Before changing the tuner XF-3SDT-H + S2, if there is no possibility of tuning to television channels, you should make sure that there are supply voltages that must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention TV owners! Attempts at self-repair of SHIVAKI STV-24LED15 are not recommended by the manufacturer and can lead to serious negative consequences!

FIRMWARE FOR SPI FLASH  ----------->   SHIVAKI STV-24LED15, Main: TP.S512.PA63, Panel: HV236WHB-N00 M00.

 The appearance of MainBoard TP.S512.PA63 is shown in the figure below:
TP.S512.PA63
TP.S512.PA63 can be used in TVs:
AIWA 24LE7021 (Panel V236BJ1-P03), ERISSON 22LES71T2 (Panel A215EE1TBA-9), FUSION FLTV-24H100T (Panel CM238C01), SUPRA STV-LC22T800FL (Panel C215F14-E1-P), THOMSON T24E14DF-01B (Panel HM236WU3-101). .
Main features of the SHIVAKI STV-24LED15 device:
Installed matrix (LED-panel) HV236WHB-N00 M00.
To power the backlight LEDs, a converter is used, combined with the TP.S512.PA63 main board, controlled by the SN51DP PWM controller. As the power elements of the LED driver, keys of the type PA1108DA are used.
The power module is combined with the MainBoard and is made according to the scheme of a flyback AC / DC voltage converter using LD5530 chips and power switches of the N-FET TO-252 type.
MainBoard - the main board (motherboard) is a TP.S512.PA63 module, using CPU chips: S2T512, SPI Flash: GD25Q64, Audio: YD1517P and others.
The XF-3SDT-H + S2 tuner provides TV reception and channel tuning.
TV SHIVAKI STV-24LED15W with LCD, diagonal size 24 "(61 cm) 16: 9 format. The required brightness of the screen 220 cd / m² is provided by LED backlight LED. Contrast, as the ratio of maximum brightness to minimum, is 1000: 1 The LED-panel of this TV is equipped with LED end-lighting - Edge LED. You can view HD images at a resolution of 1366x768 pixels in the standard for graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog P systems AL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
The power of the sound system 6 W (2x3 W) provide two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, SCART, VGA, HDMI, USB. 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, 1360x768.
The digital tuner is capable of receiving television channels in the standards DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2.
Overall dimensions: With a support of 560x385x170 mm, Without a support of 560x340x35 mm.
TV Weight: 4 kg.
Attention! The panel of the SHIVAKI STV-24LED15W 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.