Memahami sistem kerja LED TV

Summary

This video explains the basic working system of LED/LCD TVs by breaking down each major block in a clear, practical way. It starts with the power supply, describing standby voltage (around 3.5V) and how full operating voltages (12V and 24V) are activated when the TV is turned on. The 24V supply drives the inverter and backlight, while 12V feeds regulators that generate panel control signals such as VGH and VGL. The mainboard is explained as the control center for image and sound. The creator also shares common fault examples and invites viewers to ask questions for deeper troubleshooting discussions.

Takeaways

• 😀 Understanding the basic working principle of LED TVs, LCDs, and plasma TVs, with a focus on the differences in the backlighting system.
• 😀 The power supply provides DC voltage to each component, starting with a 3.5V standby voltage before the system is powered on.
• 😀 The 3.5V standby voltage keeps the TV in a standby mode, indicated by the red light on the TV, with no other voltages active.
• 😀 When the TV is turned on using the remote or a button press, the power-on signal is sent to the power supply to activate 12V and 24V voltages.
• 😀 The 24V voltage is used to power the inverter, which activates the backlight lamps in LED TVs.
• 😀 The 12V voltage powers a regulator IC, which is responsible for generating signals needed to display images on the screen.
• 😀 The regulator IC produces VGH, VDL, and VGA ON signals to activate the panel and maintain continuous image display.
• 😀 The mainboard controls all TV functions, including signal input (from the antenna) and output (video and audio).
• 😀 Common issues with the mainboard can lead to malfunctions, such as no image or sound, which can be easily diagnosed by understanding the system.
• 😀 The video aims to simplify understanding by combining theoretical explanations with real-world examples of common issues and repairs.
• 😀 Future videos will delve deeper into detailed workings of the power system, mainboard, and regulator IC to offer more in-depth knowledge.

Q & A

What is the main difference between LED, LCD, and Plasma TVs?

The main difference between LED, LCD, and Plasma TVs lies in their backlighting system. LED TVs are a type of LCD TV, but they use LED lights for backlighting, which makes them more energy-efficient and thinner. Plasma TVs use a different technology that involves ionized gases to produce light and color, which results in better contrast and color accuracy but consumes more energy.

What is the role of the DC power supply in a TV system?

The DC power supply is responsible for distributing the voltage required by different components of the TV. Initially, it provides a standby voltage of 3.5V, and when the TV is turned on, it sends power to the main board to activate higher voltages (12V and 24V) required for other components.

What happens when the TV is in standby mode?

In standby mode, only the 3.5V standby voltage is supplied, meaning the TV's power indicator (usually a red light) is on, but the TV is essentially off. No other voltage outputs (12V or 24V) are provided until the TV is powered on.

How is the 12V and 24V power used in the TV system?

The 24V power is used to generate an inverter signal that powers the backlight (LED lights) of the TV. The 12V power is used to drive a regulator IC that controls the voltage to the display panel, enabling the TV to show images.

What is the function of the inverter signal in the TV?

The inverter signal is crucial for activating the backlight of the TV. In LED TVs, this signal helps power the LED lights that illuminate the screen, making the image visible to the viewer.

What role does the mainboard play in the TV?

The mainboard acts as the central control unit of the TV. It manages the input signals, such as those from the antenna, and sends signals to the display and audio components. It is responsible for overall system coordination and communication.

How does the mainboard control the image display on the TV?

The mainboard sends a regulated signal to the display panel through the regulator IC, which powers the components necessary for displaying images. It also controls other functions like video processing and image output to the screen.

What is a common issue that can occur with the mainboard?

A common issue with the mainboard is failure to process or route signals properly, which can lead to a blank screen or malfunctioning display. The speaker also mentions encountering cases where the mainboard was the source of the problem.

What is the purpose of the voltage regulator IC?

The voltage regulator IC is responsible for controlling the voltage that powers the display panel. It ensures that the correct voltage is delivered to the panel for proper image rendering.

Can viewers troubleshoot TV issues based on this explanation?

Yes, viewers can troubleshoot TV issues by understanding how the system works. If a problem arises, they can identify potential failures in components like the power supply, mainboard, or display panel, and address issues based on the symptoms described in the video.