Tuesday 1 September 2020

REPAIRING / SERVICING TV GOLDSTAR LT-24A300F

Technical description and composition of the GOLDSTAR LT-24A300F TV, panel type and modules used. The composition of the modules.
GOLDSTAR LED
Model: LT-24A300F
Chassis / Version: V2M10
Panel: M236HGE-P01
LED driver (backlight): integrated into PSU
PWM LED driver: OB3362RP
Power Supply (PSU): HKC-PL01 REV.3.0
PWM Power: PWM SOT23-6
MOSFET Power: SVF7N65F
MainBoard: T.VST29.61C 12512
IC MainBoard: CPU: TSUMV59XE-Z1, FLASH: W25Q32BSIG
Tuner: CDT-3SP5I2-36
LT-24A300F Specifications
GOLDSTAR LT-24A300F
General recommendations for TV LCD LED repair
Possible malfunctions
- GOLDSTAR LT-24A300F TV does not turn on at all. Control lamps do not light up or blink. The TV on the remote control and control panel buttons does not respond.
In some of these cases, a malfunction is detected in the HKC-PL01 power module. 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 breakdowns in the secondary circuits of the converter, it can usually work in an emergency mode in a short circuit mode, and with a short circuit in the power elements of the primary circuit, the mains fuse or current sensor in the source of the key is most often cut off.
Breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM regulators (PWM) PWM SOT23-6, if they do not have visible damage to the case and an open short circuit between the pins, are usually checked by replacing.
- 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.
Usually, in such cases, a malfunction is detected in the LED panel backlight nodes. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED bars for a break without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters tend to light one 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as an indicator of serviceability. In faulty LEDs, the zener diode will either be cut off, or pierced in the K / Z.
- 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). When repairing an MB board, you need to check its components CPU: TSUMV59XE-Z1, FLASH: W25Q32BSIG. Defective elements should be replaced. If chips with BGA soldering technology are used, the problem in its implementation is detected by local heating of the chip.
The malfunction of the CDT-3SP5I2-36 tuner is established after checking the software and all supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be monitored with an oscilloscope.
Remember! Attempts to self-repair the GOLDSTAR LT-24A300F TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   GOLDSTAR LT-24A300F V2M10, Main: T.VST29.61C 12512, Panel: M236HGE-P01


 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 Rset resistor (in kilo-ohms) is determined from the ratio 3000 * 1.2V / Rset.
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Additional 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-24A300F device:
Installed matrix (LED-panel) M236HGE-P01.
A converter combined with a power supply is used to power the backlight LEDs and is controlled by the OB3362RP PWM controller.
The formation of the necessary supply voltages for all nodes of the GOLDSTAR LT-24A300F TV is carried out by the HKC-PL01 power module, or its analogs using PWM SOT23-6 microcircuits and SVF7N65F power switches.
MainBoard - the main board (motherboard) is a T.VST29.61C module, using CPU: TSUMV59XE-Z1, FLASH: W25Q32BSIG and others.
The CDT-3SP5I2-36 tuner provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CMO
Model: M236HGE-P01
Type: a-Si TFT-LCD, CELL
Diagonal size: 23.6 inch
Resolution: 1920x1080, FHD
Display Mode: TN, Normally White, Transmissive
Active Area: 521.28x293.22 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Transmissivity: 6.3% (with Polarizer)
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit)
Response Time: 1.5 / 3.5 (Tr / Td)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 6/8-bit), 30 pins
Voltage: 5.0V
GOLDSTAR LT-24A300F TV with LCD M236HGE-P01, 24 "(61 cm) diagonal 16: 9. The required brightness of the screen of 250 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 14000: 1 is achieved by special control of LED operation 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 films in high quality HD at a resolution of 1920x1080 pixels in graphic resolution in 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 formation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p.
The power of the sound system of 6 W (2x3 W) is 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: 571x405x155 mm.
TV weight: 4.04 kg.
Attention! Panel M236HGE-P01 LED-TV GOLDSTAR LT-24A300F 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.