Monday 27 April 2020

REPAIR / SERVICING TV HYUNDAI H-LED28V8

Technical description and composition of the HYUNDAI H-LED28V8 TV, panel type and applicable modules. The composition of the modules.
Hyundai LED
Model: H-LED28V8
Chassis / Version: 40-MS82-MT
Panel: ST2751A01-2
Power Supply (PSU): 40-ES2820
MainBoard: 40-MS82-MT-MAB2HG
IC MainBoard: CPU: MST6M30QST, Flash: EN25Q32B
Technical Specifications H-LED28V8
HYUNDAI H-LED28V8
General repair guidelines for TV LCD LED
Hyundai H-LED28V8, like other televisions, it is advisable to start repairing with a careful examination of the external and internal elements and modules. Often, by the external signs and nature of the damage to the elements, it becomes possible to draw some conclusions and determine a further algorithm for finding a defect before making the necessary measurements at control points. Swollen electrolytic or cermet capacitors, charred resistors, ring cracks in the soldered terminals of the elements - all this can significantly help the master to determine the causes and consequences of the malfunction of the TV.
If the power supply module 40-ES2820 malfunctions, the external manifestations may be different, for example, the Hyundai H-LED28V8 does not turn on at all and there is no indication of the indicator lights on the front panel. With the same symptoms, the stabilizer (converter) of the power supply to the control processor may be faulty. Diagnostics and repair of the common power supply should always begin with a check of the mains fuse and the condition of the electrolytic capacitors of the secondary rectifier filters. Defective and swollen capacitors should be replaced with new ones. If the fuse breaks, it is advisable to check for a breakdown, first of all, all the power semiconductor elements of the converter and the diode bridge of the rectifier network, as well as the large electrolytic capacitor of the filter of the rectifier network.
It should be remembered that in the practice of repair, usually the power switches in switching power supplies (SMPS) do not fail due to their poor quality and, in such cases, it is necessary to look for the cause that led to a malfunction and provoked a breakdown of the key. Most often, the culprits of the accident are dried electrolytic capacitors or dangling resistors in the primary circuit, or the PWM controller chip itself may be faulty. It is also necessary to check all the semiconductor elements of the stabilization circuit in the primary and secondary circuits.
If the Hyundai H-LED28V8 does not have an image, there is sound and the channels are switched, there is a possibility of a malfunction in the chain of ST2751A01-2 backlight LEDs, or their power converter - LED drivers. Sometimes when you turn on the image appears and disappears immediately. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the LED driver itself, including in the secondary rectifier of the main PSU.
To check the health of the LEDs, as well as contact connections in the ruler circuit, it is necessary to disassemble the panel.
To detect a break in the LED lines without disassembling the panel, a current source is required. It is impossible to open transitions connected in series with a simple multimeter; voltage of several tens of volts is necessary.
In cases of attempts to repair the 40-MS82-MT motherboard, it is necessary to check the performance of the stabilizers or power converters of its microcircuits and, if possible, update the software (software). BGA chips can in most cases be diagnosed by local heating.
In some cases, it is necessary to check or replace (if necessary) the elements of the MB board (SSB) - CPU: MST6M30QST, Flash: EN25Q32B. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
Once again, remind users! Attempts to independently repair a Hyundai H-LED28V8 TV without the appropriate qualifications and experience can lead to its complete non-repairability!


FIRMWARE FOR SPI FLASH  ----------->   Hyundai H-LED28V8, Main 40-MS82-MT, Panel ST2751A01-2



 If a failure occurs in the SPI FLASH Winbond software, we recommend that you replace the chip with a new one. In addition, faulty Winbond microcircuits can sometimes recover for a while after being heated by a soldering station or even a lighter, which is enough to read its regular contents.
Main features of the HYUNDAI H-LED28V8 device:
Installed matrix (LED panel) ST2751A01-2.
The formation of the necessary supply voltages for all nodes of the HYUNDAI H-LED28V8 TV is carried out by the 40-ES2820 power supply module, or its analogs.
MainBoard - the main board (motherboard) is a 40-MS82-MT-MAB2HG module, using CPU chips: MST6M30QST, Flash: EN25Q32B and others.
Additional technical information about the panel:
Brand: CSOT
Model: ST2751A01-2
Type: a-Si TFT-LCD, CELL
Diagonal size: 27.5 inch
Resolution: 1366x768, WXGA
Display Mode: HVA, Normally Black, Transmissive
Active Area: 607.528x345.024 mm
Surface: Antiglare (Haze 2%), Hard coating (3H)
Glass Depth: 0.70 + 0.70 mm
Transmissivity: 7.2% (with Polarizer)
Contrast Ratio: 3000: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 62%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Signal Interface: Mini LVDS, 60 pins
Voltage: 5.0V
 HYUNDAI H-LED28V8 TV with ST2751A01-2 LCD display, diagonal size 28 "(71 cm) in 16: 9 format. The required screen brightness of 250 cd / m² is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 3000: 1. Edge LED backlighting is implemented in the LED-panel of this TV - Edge LED. High quality HD images can be viewed at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems . Max PAL, SECAM, NTSC Image processing and the formation of the digital signal is in 480i standards, 480p, 576i, 576p, 720p, 1080i Supported multimedia file formats:. MP3, WMA, MPEG4, Xvid, DivX, MKV, JPEG.
The power of the sound system 10 W (2x5 W) provide two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV x2, audio x2, component, VGA, HDMI, USB. 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, 1360x768.
Attention! The HYUNDAI H-LED28V8 LED TV panel ST2751A01-2 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.