Tuesday, 1 September 2020

REPAIRING / SERVICING TV GOLDSTAR LT-22T305F

Technical description and composition of the GOLDSTAR LT-22T305F TV, panel type and modules used. The composition of the modules.
GOLDSTAR LED
Model: LT-22T305F
Chassis / Version: V1N02, V1N04
Panel: HK215WLEDM - DH67H
LED backlight: EDGE LED
LED driver (backlight): 12V Led Driver
Power Supply (PSU): Adapter 12V
MainBoard: CV9202L-T
IC MainBoard: CPU: SPV9202BD, Spi Flash: 25Q64, DDRAM: W6310GKB-12, SOUND: YD1517
Tuner: ST03WS-2A-E
LT-22T305F Specifications
GOLDSTAR LT-22T305F
General recommendations for TV LCD LED repair
Possible manifestations of defects
- TV GOLDSTAR LT-22T305F does not turn on and does not show any signs of operability at all. No response to the remote control and front panel control buttons.
With similar manifestations, in some cases the adapter power supply module is faulty.
This TV model is equipped with an external power supply of the Adapter 12V type, which the owner can purchase on his own, and its repair may not always be advisable, however, sometimes it makes sense to open it and eliminate simple typical defects typical for SMPS. Its output voltages should be measured and, in their absence, the serviceability of the power switches and rectifier diodes in the converters should be checked for possible breakdown.
In case of breakdowns in the secondary circuits, the converter can operate in a short-circuit mode, and in case of a short circuit in the elements of the primary circuit, the mains fuse is usually cut off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements, which can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying the PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM), in the absence of external damage and a short circuit between the terminals, are checked by replacing them with a known good one.
- There is no picture, there is sound, it reacts to the remote control, the channels are switched. In some cases, the image appears when turned on and disappears immediately.
In some of these cases, the malfunction is caused by the lack of display backlighting. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
When trying to detect a break in the LED lines, it should be borne in mind that it is difficult to do this without disassembling the panel. For example, a current source is required to open PN junctions connected in series.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the CV9202L-T 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). Complicated MB (SSB) repair is possible only in the conditions of a service center with the necessary equipment. Checking or replacing CPU elements: SPV9202BD, Spi Flash: 25Q64, DDRAM: W6310GKB-12, SOUND: YD1517 requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by the warm-up method.
If there is no reception of TV channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the ST03WS-2A-E tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.
Owners and users of the GOLDSTAR LT-22T305F TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences, which can lead to complete non-repairability of the device!



DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   GOLDSTAR LT-22T305F V1N04, Main: CV9202L-T, Panel: HK215WLEDM - DH67H
 The appearance of the MainBoard CV9202L-T is shown in the figure below:
CV9202L-T
The MainBoard CV9202L-T uses an SPV9202BD processor, W6310GKB-12 RAM and 8Mb SPI FLASH ROM.
It is advisable to start repairing the motherboard with checking all voltage converters and linear stabilizers necessary to provide power to the nodes and chips in operating and standby mode. The processor core is powered by + 1V. Also, for the SPV9202BD to work, voltages of + 2.5V and + 3.3V are required. Check the LCD panel power supply (depending on the type, + 5V or + 12V), it is convenient to measure directly on the LVDS connector. If, with the necessary supply voltages, the TV does not come out of Stand-by mode, does not respond to the Remote Control and control buttons, you should update the SPI Flash 25Q64 firmware.
CV9202L-T can be used in TVs:
AIWA 24LE7020 (Panel V236BJ1-P01), BBK 22LEM-1006/FT2C (Panel M215HTN01.1 KM215N19-AU-01), DEXP 19A3100 (Panel CX185LEDM), DEXP 22A7100 (Panel T215HVN01.0 M215HVN01.0), FUSION FLTV-24T22 (Panel M236HGE-P02), FUSION FLTV-22T22 (Panel 720p HD 1366x768), SHIVAKI STV-24LED14 (Panel V236BJ1-P01 / CX236LEDM), SUPRA STV-LC24T410FL (Panel M236HGE-P01), SUPRA STV-LC19T410WL (Panel HK185WLEDM CH25H), SUPRA STV-LC22T410FL (Panel LC215DT5A), SUPRA STV-LC24T410WL (Panel HK236WLEDM-CH24H), SUPRA STV-LC19T880WL (Panel LC185TT7A).
Main features of the GOLDSTAR LT-22T305F device:
Installed matrix (LED panel) HK215WLEDM - DH67H.
A 12V LED driver is used to power the backlight LEDs.
To power all the internal units of the GOLDSTAR LT-22T305F TV, an external adapter 12V is used.
MainBoard - the main board (motherboard) is a CV9202L-T module using CPU chips: SPV9202BD, Spi Flash: 25Q64, DDRAM: W6310GKB-12, SOUND: YD1517 and others.
The ST03WS-2A-E tuner provides reception of television programs and tuning to channels.
GOLDSTAR LT-22T305F TV with LCD HK215WLEDM-DH67H, 22 "(56 cm) 16: 9 diagonal. The required screen brightness of 250 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 60,000: 1 is achieved by special control of LED operation The LCD-panel of the TV is equipped with direct backlighting with rear-mounted LEDs - Direct LED.The design and technical capabilities of the TV provide viewing of broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in graphic resolution in accordance with the standard 1080p (Full HD) .Input high-frequency or video signal. can be processed in analog systems PAL, SECAM, NTSC Graphic processing and digital signal shaping occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p Supported media file formats: MP3, WMA, MPEG4, DivX, JPEG.
Speaker power of 6 W (2x3 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), component, SCART, VGA, HDMI, USB. A headphone output is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector on the TV case is used, this interface supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768.
The digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Dimensions: without stand 530x370x55 mm.
TV weight: without stand: 4 kg.
Attention! Panel HK215WLEDM-DH67H LED TV GOLDSTAR LT-22T305F is an expensive and unreliable element.
Do not allow any impact 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 unrepairable.