Tuesday 1 September 2020

REPAIRING / SERVICING TV GOLDSTAR LT-40T450F

Technical description and composition of the GOLDSTAR LT-40T450F TV, panel type and modules used. The composition of the modules.
GOLDSTAR LED
Model: LT-40T450F
Chassis / Version: V1P11
Panel: RDL400FY V400HJ6-PE1 (C1)
LED backlight: 5800-W40000-2P00 VER1.0
T-CON: V400HJ6-PE1
LED driver (backlight): integrated into MainBoard
PWM LED driver: TPS61196
MOSFET LED driver: AOD4286
Power Supply (PSU): integrated into MainBoard
MainBoard: 5800-A6M30G-0P00 VER00.00
IC MainBoard: CPU: MSD3463GSA, SPI Flash: 25Q64CSIG, Audio: TPA3113D2, MP8126, Z3015A1
Tuner: CP
LT-40T450F Specifications
GOLDSTAR LT-40T450F
General recommendations for TV LCD LED repair
Possible malfunctions
- TV GOLDSTAR LT-40T450F 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 AC / DC converter of the mains voltage, which is combined with the 5800-A6M30G-0P00 main board, is often faulty. Then you should measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of the power switches and rectifier diodes of the converters for a possible short circuit.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks 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 controllers (PWM), if they do not have visible damage to the case and an outright short circuit between the terminals, are usually checked by replacement.
- 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 may be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To check the LED strips for breakage without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter; a voltage of the order of several tens of volts is required.
- 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 5800-A6M30G-0P00 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). If it is not possible to replace the MB (SSB) board, it is necessary to check the serviceability of its elements - CPU: MSD3463GSA-W2, SPI Flash: 25Q64CSIG. Defective components must be replaced.
In cases where 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 CP tuner outputs match. 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 self-repair the GOLDSTAR LT-40T450F TV without appropriate qualifications and necessary experience can lead to serious negative consequences!



DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   GOLDSTAR LT-40T450F Version: V1P11, Main: 5800-A6M30G-0P00 VER00.00, Panel: RDL400FY V400HJ6-PE1 (C1) 


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   GOLDSTAR LT-40T450F V1R04 Panel: RDL400HJ6-PE1 (C1), MainBoard: 5800-A6M30G-0P00 VER00.00

 LED current in the panel = 360 mA, if R0B9 82 kOhm resistor REPLACE BY 150 kOhm, CURRENT = 260 mA.
To reduce the backlight current in LED drivers with a TPS61196 controller, you should proportionally increase the total resistance of the resistors from pin 10 (ISET) to the case. The maximum current in each of the six channels (in milliamperes) for the resistor Rset (in kilo-ohms) is determined from the ratio 3992 * 1.229V / Rset. In channels connected in parallel, the currents are added.
Additional MainBoard Repair
The appearance of the MainBoard 5800-A6M30G-0P00 is shown in the figure below:
5800-A6M30G-0P00
Main features of the GOLDSTAR LT-40T450F device:
Installed matrix (LED panel) RDL400FY V400HJ6-PE1 (C1).
Matrix control uses the Timing Controller (T-CON) V400HJ6-PE1.
To power the backlight LEDs, a converter combined with the 5800-A6M30G-0P00 main board is used, controlled by the TPS61196 PWM controller. The keys of the AOD4286 type are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback converter circuit.
MainBoard - the main board (motherboard) is a 5800-A6M30G-0P00 module, using CPU chips: MSD3463GSA, SPI Flash: 25Q64CSIG, Audio: TPA3113D2, MP8126, Z3015A1 and others.
The CP tuner provides TV reception and channel tuning.
GOLDSTAR LT-40T450F TV with LCD RDL400FY, diagonal size 40 "(102 cm) 16: 9 format. The required brightness of the screen of 250 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 100,000: 1 is achieved by special control of the LEDs. The technology of manufacturing the screen of this TV model is implemented with LED backlighting.The design and technical capabilities of the TV provide for viewing programs and films 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 is performed in 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards Supported multimedia file formats: MP3, WMA, MPEG4, MKV, JPEG.
Speaker power of 6 W (2x3 W) is provided by two speakers. The 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), SCART, VGA, HDMI x2, MHL, USB. 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, 1360x768.
The digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2 standards.
Attention! Panel RDL400FY LED TV GOLDSTAR LT-40T450F 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.