👉 Sony Bravia Led rojo enciende 6 veces [RESUELTO💯] Problema de parpadeo Electronica Nuñez👉❤️

ELECTRÓNICA NÚÑEZ TUTORIALES

26 Jul 201914:01

Summary

TLDRIn this video, the presenter demonstrates troubleshooting a common issue with a Sony Bravia TV, where it fails to stay on due to backlight problems. After identifying that the TV enters protection mode due to LED backlight failures, the presenter uses an oscilloscope to diagnose the problem. They provide step-by-step instructions on how to bypass the TV's protection mechanism using a resistor to ground the control pin. This method allows the TV to function without disassembling the screen further. The video concludes with confirming that the LEDs are working correctly, restoring full functionality.

Takeaways

🔌 The video demonstrates how to troubleshoot a common issue with a Sony Bravia TV that enters protection mode.
🔴 When powered on, the TV shows the Sony logo briefly, then turns off and flashes red in standby mode, indicating a backlight protection issue.
🔦 The problem likely lies with the backlight controller or one of the LED strips, but it is not necessary to disassemble the TV fully to resolve the issue.
📏 The creator uses an oscilloscope to check the return pulses from the LED strips, setting it to 2 volts per division and 500 microseconds.
📊 By measuring the return voltages from the three LED strips, the technician confirms that each returns a consistent 4 volts, ruling out damaged LED strips.
💡 The next step is to analyze the signals from the backlight controller, specifically checking the error detection and pulse communication.
🔧 The technician targets pin 31 on the controller IC, associated with the error line, to monitor the pulse response using the oscilloscope.
⚡ The problem is resolved by connecting a 10,000-ohm resistor between pin 31 and ground, eliminating the error pulse and enabling the backlight to stay on.
📺 After the repair, the backlight functions correctly, and there are no signs of faulty LEDs or dark spots on the screen.
✅ The video concludes with the technician verifying the TV works properly by connecting an HDMI source, showing that the screen displays as expected without further issues.

Q & A

What is the common issue being addressed in the video?
-The video addresses a common issue with Sony Bravia screens where the backlight fails, causing the TV to enter protection mode and display a green color, followed by red standby light indicating the problem.
What does the green color on the screen indicate?
-The green color on the screen indicates that the divider has been turned on and the TV is starting up.
What does the red standby light signify?
-The red standby light signifies that the TV has entered protection mode, indicating a problem with the backlight.
What could be the possible causes of the backlight failure?
-The possible causes of the backlight failure could be a faulty backlight controller, damaged LEDs, or a specific LED that is not functioning properly.
What is the purpose of eliminating the protection mode in the tutorial?
-Eliminating the protection mode is intended to force the TV to turn on the LEDs, which might still be in good condition, thereby giving the TV some utility without needing to disassemble it further.
What is the first step the presenter takes to diagnose the issue?
-The first step the presenter takes is to disassemble the TV and locate the backlight controller to diagnose the issue.
Why does the presenter suggest that disassembling the screen might not be necessary?
-The presenter suggests that disassembling the screen might not be necessary because sometimes the issue is with just one LED, and the rest of the LEDs might still function correctly.
What diagnostic test does the presenter perform to check the LED strips?
-The presenter performs a diagnostic test using an oscilloscope to check the return pulse from each LED strip to determine if any are damaged.
What do the three flashes on the screen typically indicate?
-Typically, three flashes on the screen indicate that there is a problem with the TV's backlight, and it is entering protection mode.
What does the presenter conclude after checking the return pulse from the LED strips?
-After checking the return pulse, the presenter concludes that the failure is not due to damaged LED strips since all three reference points of return voltage are showing 4 volts each.
How does the presenter determine the functioning of the backlight controller?
-The presenter determines the functioning of the backlight controller by observing the signals on the data points of the integrated circuit, specifically looking at the clk, error, cp, pwm, and ddm signals.
What is the significance of the line CP in the context of the video?
-The line CP is significant because it can indicate problems with the integrated circuit if there is an error in frequency or signal level, leading to the TV entering protection mode.
What is the solution the presenter applies to resolve the issue?
-The presenter resolves the issue by connecting a resistor between pin 31 of the controller and the negative ground (chassis) to bypass the error signal.
How does the presenter verify that the LEDs are functioning correctly after applying the solution?
-The presenter verifies that the LEDs are functioning correctly by checking for uniform lighting and connecting an HDMI signal to display a white screen, ensuring there are no dark spots or shadows indicating damaged LEDs.

Outlines

00:00

🔌 Introduction to Common Sony Bravia TV Issue

The video begins with an introduction to a common issue faced by Sony Bravia TVs, where the TV enters protection mode due to backlight failure. The presenter connects the TV to power and observes that the Sony logo appears briefly before the screen goes black, followed by red standby light flashes. This indicates that the backlight is malfunctioning. The issue may be related to the backlight controller or specific LED strips. The presenter explains that the video will demonstrate how to bypass this protection mode to get the TV functioning without extensive repairs.

05:04

🔍 Diagnosing Backlight Controller and LED Strips

The presenter disassembles the TV to investigate the backlight controller, explaining that the problem is often caused by damaged LED strips. However, instead of disassembling further, the presenter opts to test the return signals from the LED strips using an oscilloscope. They explain the setup: adjusting the oscilloscope to 2 volts per division and 500 microseconds per division to measure the pulses. The test reveals a consistent 4-volt pulse return from all three LED strips, indicating that the LEDs themselves are not faulty. This rules out LED strip damage as the cause of the problem.

10:06

📊 Investigating the Backlight Controller Chip

The presenter shifts focus to the backlight controller chip, specifically a 9327 model. They explain the role of key signals, such as the return pulse, clock, and error lines. The return pulse tests indicate no issue, so the error lies in another signal. The error signal, triggered by the controller chip, is responsible for the protection mode. The presenter measures the error pulse at pin 31 of the chip, adjusting the oscilloscope to 1 volt per division. The test reveals a 2-volt pulse, confirming the error line is causing the TV to enter protection mode.

⚡ Bypassing the Error Signal to Restore Function

To resolve the issue, the presenter demonstrates how to bypass the error signal by grounding pin 31 of the controller chip using a 10,000-ohm resistor. After connecting the resistor between pin 31 and the chassis ground, they power on the TV and observe that the backlight LEDs illuminate correctly without the previous 2-volt error pulse. The TV successfully bypasses the protection mode, and the LEDs remain on.

📺 Testing TV Display for LED and Image Quality

The presenter tests the TV display by connecting an HDMI signal and displaying a white screen. This ensures that all LEDs are functioning properly and there are no dark spots or shadows, which would indicate damaged LEDs. The white screen displays evenly, confirming that all LEDs are working. The presenter concludes by noting that the simple bypass technique successfully resolved the issue with the Sony Bravia TV, without needing to replace any LED strips or perform more invasive repairs.

Mindmap

Keywords

💡Backlight

The backlight is a component in LED and LCD displays that provides illumination from behind the screen, allowing the image to be visible. In the video, the technician identifies the backlight as the source of the issue with the Sony Bravia TV, stating that a malfunction in the backlight or one of the LEDs might be causing the television to enter protection mode.

💡Protection mode

Protection mode is a safety feature in electronic devices that prevents further damage by shutting down the system when an issue is detected. In the video, the Sony Bravia TV enters protection mode due to a detected fault in the backlight, indicated by the red blinking standby light. The technician aims to bypass this mode to determine the underlying problem.

💡LED reglets

LED reglets refer to the series of LEDs used in the backlight assembly of the TV. The technician tests these reglets to check for any defective LEDs that might be causing the TV to enter protection mode. Proper functioning of all LED reglets ensures that the backlight works correctly, providing even illumination across the screen.

💡Oscilloscope

An oscilloscope is an electronic instrument used to observe the varying signal voltages in an electronic system. In the video, the technician uses an oscilloscope to measure the return pulse from each of the LED reglets to verify if they are functioning correctly. The oscilloscope is set to 2 volts per division and 500 microseconds per division for accurate readings.

💡Return pulse

The return pulse is the feedback signal from the LED reglets that indicates whether they are operating within expected parameters. The technician measures the return pulse from each reglet, noting that all of them produce a consistent 4 volts, which suggests that the LEDs themselves are not faulty, and the issue lies elsewhere.

💡Integrated controller

The integrated controller is a chip responsible for managing the backlight's operation, including error detection and LED monitoring. The technician inspects the integrated controller of the backlight system to understand the error signals and the behavior of the system when protection mode is triggered. Specifically, they check pin 31 for error signals.

💡Pin 31

Pin 31 is a specific connection on the integrated controller that the technician examines to identify error signals related to the backlight. By observing the signal at pin 31, the technician identifies a 2-volt error pulse, which is causing the TV to enter protection mode. The technician decides to modify the signal at pin 31 to resolve the issue.

💡Error pulse

An error pulse is a signal generated by the integrated controller when it detects a malfunction in the backlight system. In the video, the technician finds that pin 31 produces an error pulse of 2 volts, which triggers the TV's protection mode. By grounding this pulse using a resistor, the technician aims to prevent the error signal and allow the TV to function normally.

💡Resistor

A resistor is a passive electrical component used to limit or regulate the flow of electrical current. The technician uses a 10,000-ohm resistor to connect pin 31 to the ground, effectively bypassing the error signal and stopping the TV from entering protection mode. This allows the backlight to remain on and the TV to function without triggering a shutdown.

💡HDMI signal

The HDMI (High-Definition Multimedia Interface) signal is used to transmit high-quality video and audio between devices. In the video, the technician connects an HDMI signal to verify that the TV screen displays correctly without any dark spots, indicating that all LEDs are functioning properly after the modification to the integrated controller.

Highlights

Introduction of the issue with a Sony Bravia screen, experiencing one of the most common failures.

Description of how the TV enters protection mode, as indicated by red flashes in the standby light.

Identification of the issue in the backlight system, potentially caused by the backlight controller or a faulty LED.

The goal of the tutorial is to bypass the protection and use the TV without full disassembly.

The presenter disassembles the TV to access the backlight controller and performs a diagnosis of the LED strips.

Explanation of using an oscilloscope to check the return pulses from the LED strips, indicating if the LEDs are functioning correctly.

Demonstration of detecting a 4V return pulse from each LED strip, indicating that the LED strips are working properly.

Conclusion that the issue is not due to damaged LED strips, but may be related to the backlight controller IC.

Discussion of the backlight controller IC’s operation, including how error signals are triggered.

Verification of the error pulse using an oscilloscope, showing that the IC triggers the error signal when an anomaly is detected.

Solution: Grounding pin 31 of the backlight controller IC using a 10,000-ohm resistor to bypass the protection circuit.

Confirmation that the TV successfully powers on with all LEDs functioning properly after bypassing the protection.

Final test: Connecting the TV to an HDMI source to verify that the display works and no LEDs are damaged.

Explanation that any dark spots on the screen would indicate damaged LEDs, but in this case, the screen is fully lit without issues.

Summary: The tutorial successfully bypasses the backlight protection on a Sony Bravia TV, restoring functionality without replacing the LED strips.