Tuesday 1 September 2020

REPAIRING / SERVICING TV GOLDSTAR LT-22A305F

Technical description and composition of the GOLDSTAR LT-22A305F TV, panel type and modules used. The composition of the modules.
GOLDSTAR LED
Model: LT-22A305F
Chassis / Version: V2L12
Panel: LM215DA-T01 HK215WLEDM-DH24H
LED backlight: Edge LED 60 mA
T-CON: RUNTK0001ZAPN; i7814HP, MST7346F-LF
LED driver (backlight): integrated into PSU; 60 mA
PWM LED driver: OB3362RP
Power Supply (PSU): HKC-PL01
PWM Power: SG6848 (PWM SOT23-6)
MOSFET Power: SVF7N65F
MainBoard: T.VST29.61C 12296
IC MainBoard: CPU: TSUMV59XE-Z1, SPI FLASH: 25Q32, AUDIO: YD1517P
Tuner: DT-3SP512-36
LT-22A305F Specifications
GOLDSTAR LT-22A305F
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- TV GOLDSTAR LT-22A305F does not turn on at all. No response to the remote control and front panel control buttons. Indicator lamps do not light up or flash.
In such cases, the HKC-PL01 power supply usually fails. Then we recommend measuring its output voltages and, if they are absent, you should check the serviceability of the power switches (SVF7N65F) and the rectifier diodes of the converters for a possible short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in an emergency mode of a short circuit, and with a short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key often breaks off.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers SG6848 (PWM SOT23-6), in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or known to be working properly.
- There is no picture, but there is sound and reaction to the remote control. Or, for a second, the image may appear immediately after switching on.
In some of these cases, the malfunction is caused by the lack of display backlighting. The reason can be found in the malfunction of the LEDs, in the violation of the contact connections of the LED strips, or in the provision of their power supply (LED driver).
To check the health of the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED separately with a simple Chinese multimeter (powered by 9 volts) in the P-N transition test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black one to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. The serviceability of the PN junction of the Zener diode indirectly indicates the serviceability of the LED-a
- 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 T.VST29.61C 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 cases of attempts to repair the MB (SSB) board, it is necessary to check the serviceability of its elements - CPU: TSUMV59XE-Z1, SPI FLASH: 25Q32, AUDIO: YD1517P which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its pins with the board (detected by warming up).
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 DT-3SP512-36 tuner terminals are in compliance. 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.
Users and owners of TVs should remember that attempts to repair the GOLDSTAR LT-22A305F TV on their own without the appropriate qualifications and necessary experience can lead to serious negative consequences!


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   GOLDSTAR LT-22A305F V2L12, Main: T.VST29.61C 12296, Panel: LM215DA-T01 HK215WLEDM-DH24H



 To reduce the backlight current in LED drivers with OB3362RP (TSOP16) controller, increase the total resistance of the resistors from pin 5 (ISET) to the case. The maximum current in each of the four channels (in milliamperes) for the resistor Rset (in kilo-ohms) is determined from the ratio 3000 * 1.2V / Rset.
https://2.bp.blogspot.com/-Rubv2LE8r7Q/X05KQtgfdqI/AAAAAAABFKM/zOxyYK--elojB8NbgekNAdmI1C0ExpWYgCK4BGAYYCw/s1600/HKC-PL01_DCE.jpghttps://1.bp.blogspot.com/-cXuxyonqSas/XyqjSPDM4eI/AAAAAAABDEs/qjLTgeiejHcJ-McwPejnOD5urmTrxHi1ACK4BGAYYCw/s1600/T.VST29.61C_DCE.jpgAdditional MainBoard Repair
The appearance of the MainBoard T.VST29.61C is shown in the figure below:
T.VST29.61C
T.VST29.61C can be used in TVs:
GOLDSTAR LT-24A300F (Panel M236HGE-P01), GoldStar LD-19A300R (Panel V185B1-PE1), SUPRA STV-LC19410WL (Panel M185BGE-P02 HK185WLEDM-CH15H), SUPRA STV-LC2277FL (Panel LM215DA-T01), SUPRA STV-LC22410WL (Panel LM216DA-T01), SUPRA STV-LC24410FL (Panel M236H1-P01 HK236WLEDM-CH84H ).
External view of the power supply
Main features of the GOLDSTAR LT-22A305F device:
Installed matrix (LED panel) LM215DA-T01 HK215WLEDM-DH24H.
Matrix control uses Timing Controller (T-CON) RUNTK0001ZAPN ;.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by the OB3362RP PWM controller.
The formation of the necessary supply voltages for all nodes of the GOLDSTAR LT-22A305F TV is carried out by the HKC-PL01 power module, or its analogs using SG6848 (PWM SOT23-6) microcircuits and SVF7N65F power switches.
MainBoard - the main board (motherboard) is a T.VST29.61C module, using CPU chips: TSUMV59XE-Z1, SPI FLASH: 25Q32, AUDIO: YD1517P and others.
The DT-3SP512-36 tuner provides reception of television programs and tuning to channels.
GOLDSTAR LT-22A305F TV with LCD display LM215DA-T01, 22 "(56 cm) diagonal, 16: 9. The required screen brightness of 250 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 14000: 1 is achieved by special LED control The LED panel of this TV is equipped with Edge LED backlighting.The design and technical capabilities of the TV provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to 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 takes place in 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards.
The power of the sound system is 6 W (2x3 W), 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. 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.
The power consumed by the TV operating in mains mode is 40 W.
Overall dimensions: 526x377x155 mm.
TV weight: 3.48 kg.
Attention! Panel LM215DA-T01 HK215WLEDM-DH24H LED TV GOLDSTAR LT-22A305F 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.