Thursday 23 April 2020

REPAIR / SERVICING TV SHIVAKI STV-22LEDG8

Technical description and composition of the TV SHIVAKI STV-22LEDG8, type of panel and applicable modules. The composition of the modules.
SHIVAKI LED
Model: STV-22LEDG8
Chassis / Version: M309S2IR1TA
Panel: CLAA215FA04 // M215HGE-L10
PWM LED driver: BIT3251
MOSFET LED driver: AOD478
Power Supply (PSU): Adapter 12V
MainBoard: MSD309PV7.0-A
IC MainBoard: Cpu: MSD309PX-LF-Z1, FLASH 25L32
Technical Specifications STV-22LEDG8
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LCD TV LED STV-22LEDG8
Display diagonal: 22 "(56 cm)
Screen Format: 16: 9
Resolution: 1920x1080
LED backlight: yes, Edge LED
HD Support: 1080p Full HD
Brightness: 250 cd / m2
Contrast Ratio: 1000: 1
Viewing Angle: 170 °
Pixel Response Time: 3.5 ms
Progressive scan: yes
TV Standards: PAL, SECAM, NTSC
Digital Tuner: DVB-T MPEG4
Teletext: with 750 page memory
DTV Formats: 480i, 480p, 576i, 576p, 720p, 1080i, 1080p
Multimedia: MP3, MPEG4, JPEG
Stereo sound: yes
Acoustics: two speakers
Interface: Component, SCART x2, RGB, VGA, HDMI, USB
Headphone jack: yes
SHIVAKI STV-22LEDG8
General repair guidelines for TV LCD LED
Malfunctions of the Adapter power supply module can be expressed in different ways, for example, the SHIVAKI STV-22LEDG8 does not turn on at all and the control lamps on its front panel do not light up and do not blink, and there are no signs of operability. First of all, it is necessary to replace the swollen capacitors of the rectifier filters, if any. If the mains fuse is broken in the power supply, in most cases a breakdown of the power key (s) is detected, which can be integrated with the PWM controller, or a separate field effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
It should be borne in mind that in the practice of repair it is extremely rare that key transistors in switching power supplies (SMPS) fail for no reason that should be sought by checking other components, for example, a breakdown of the key can provoke faulty elements of the damper circuits, or dried electrolytic capacitors or dangling primary resistors BP circuits involved in the stabilization process. In this case, all semiconductor elements of the strapping of the PWM controller chip are subject to verification, which it is desirable to verify by replacement.
In cases where the SHIVAKI STV-22LEDG8 TV has lost an image, and the sound is there and all the other functions are operational, there is a possibility of a malfunction of the LED driver (converter for powering the CLAA215FA04 backlight LEDs). When you turn on the TV, the image may appear briefly and disappear. It must be borne in mind that with such manifestations the LEDs themselves also fail.
The lack of backlight often occurs due to an open circuit in the LED circuit. There is a need for disassembling the panel and checking the LEDs themselves, as well as the same contact connections in the connectors and rations of the terminals.

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.

Diagnosis and repair of the motherboard MSD309PV7.0-A usually begins with a test of the performance of the stabilizers and power converters of the module chips. In some cases, a software update is required.
If it is not possible to replace the MB board (SSB), you need to check the health of its elements - Cpu: MSD309PX-LF-Z1, FLASH 25L32. Defective components should be replaced.
Attention! For users and owners of STV-22LEDG8 TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    Chassis MSD309B Schematic diagram

FIRMWARE FOR SPI FLASH  ----------->   SHIVAKI STV-22LEDG8, Main: MSD309PV7.0-A, Panel: CLAA215FA04

 The appearance of the MainBoard MSD309PV7.0-A is shown in the figure below:
MainBoard MSD309PV7.0-A uses the MSD309B processor, DDRAM random access memory (RAM) in BGA version and SPI Flash ROM type 25Q32 (4Mb).
It is advisable to start the repair of the motherboard by checking the voltage converters and linear stabilizers necessary to provide power to the nodes in operating and standby mode. The processor core is powered by + 1.5V. Also, the processor voltage requires + 2.5V and + 3.3V.
If the display backlight is working properly and there is no image, it is necessary to check the panel power (depending on the type, + 5V or + 12V), which is more convenient to measure directly on the LVDS connector. If, in the presence of all the supply voltages, the TV does not enter the operating mode, does not respond to the Remote Control and control buttons, you should update the SPI Flash firmware.
MSD309PV7.0-A can be used in TVs:
SHIVAKI STV-19LEDG7 (Panel LQ185T1LGN3), SHIVAKI STV-24LEDGR7 (Panel M236H1-L01), SHIVAKI STV-22LEDG8 (Panel CLAA215FA04).
Main features of the SHIVAKI STV-22LEDG8 device:
Installed matrix (LED-panel) CLAA215FA04 or M215HGE-L10.
A converter controlled by the BIT3251 PWM controller is used to power the backlight LEDs. As the power elements of the LED driver, keys of the AOD478 type are used.
To power all the internal components of the SHIVAKI STV-22LEDG8 TV, an external adapter 12V type is used.
MainBoard - the main board (motherboard) is an MSD309PV7.0-A module, using Cpu chips: MSD309PX-LF-Z1, FLASH 25L32 and others.
Additional technical information about the panel:
Brand: CPT
Model: CLAA215FA04 V4
Type: a-Si TFT-LCD, Panel
Diagonal size: 21.5 inch
Resolution: 1920x1080, FHD
Display Mode: TN, Normally White, Transmissive
Active Area: 476.64x268.11 mm
Surface: Antiglare, 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: 16S4P WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V
TV SHIVAKI STV-22LEDG8 with LCD display CLAA215FA04, diagonal size 22 "(56 cm) 16: 9 format. The required brightness of the screen is 250 cd / m² LED backlight LED. Contrast, as the ratio of maximum brightness to minimum, is 1000: 1. The LED-panel of this TV is equipped with end LED backlighting - Edge LED.The design and technical capabilities of the TV include viewing programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphic layout according to the standard 1080p (Full HD). frequency or video signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, MPEG4, JPEG. Stereo audio implemented by two built-in speakers, NICAM STEREO audio processing system is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), component, SCART x2, RGB, 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, 1024x768, 1280x1024, 1360x768.
The digital tuner is capable of receiving television channels in DVB-T MPEG4 standards.
Overall dimensions: With a support of 581x406x180 mm, Without a support of 581x371x43 mm.
Attention! The CLAA215FA04 panel of the SHIVAKI STV-22LEDG8 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.