LED TV Black Screen Issue After Startup

LED TV Black Screen Issue After Startup – T-Con Board Diagnosis & Fix

Fault Introduction

Fix LED TV black screen after startup. This LED TV came to me for repair in the workshop. The customer said that its backlights were faulty. This LED TV was a 43-inch model of Aiwa. I said that you leave it with me. I will diagnose it and tell you what is wrong with it. However, the customer kept insisting on his point, but I kept the TV and diagnosed it. His T-CON card was found to be faulty. It was like this: When the TV was turned on, the display went blank after a while, due to which the customer also felt as if the backlights had turned off. So in this article we will see why the T-CON card is making the display blank. We will know it step by step.

• TV initially worked fine for 10 minutes, then the display went blank.
• T-CON board voltage was 3.3V (normal).
• AVDD voltage dropped to 0V — complete loss.
• Upon rechecking, AVDD showed 14V instead of required 17V.
• Meter probe interaction caused AVDD voltage to disappear again.
• Fault traced to T-Con board, specifically AVDD voltage instability.

T-Con Repair – Corroded DC IC Fixed

The chip used in this TV is a DC to DC IC from Nova Tech Company, and I examined this DC to DC IC carefully and saw that I saw corrosion between its pins. This corrosion is caused by the environment. However, I washed it. I have my own method for doing this. I use a chemical. I put it on this IC, and it removes all its corrosion. I put that chemical on it for 10 to 15 minutes. I put it on the IC, and after that I clean it with thinner. It starts working perfectly. So I did this cleaning process well and then dried it. After drying the chip, I installed it in the LED TV, and after installing it, I tested it. As soon as I tested it, I came to know that my work was done. The reason was that the AVDD voltage of 17 voltages was reached.

• Upon inspection, corrosion was found between the IC pins, caused by environmental factors.
• A special chemical was applied to remove the corrosion, left on for 10–15 minutes.
• Afterward, the IC was thoroughly cleaned using thinner and dried properly.
• Once the IC was dry, it was reinstalled into the LED TV.
• After powering on, the AVDD voltage was successfully restored to 17V, confirming the issue was fixed.

Conclusion

This is an Aiwa LED TV that I brought for repair. The customer said that its backlight was faulty, but when I diagnosed it, it was its T-con card that was faulty. We repaired this problem. As I have explained everything above, usually customers give you their logic, whereas you have to diagnose the fault and only then come to a logical conclusion. So you saw how we fixed this fault step by step in this article. This fault was such that the display would go blank after running for a while, so we solved it. If you have any questions about it, you can ask in the comments and I will answer.

Q1: Why did the AVDD voltage of the T-CON board drop and the display disappear?

A1: The simple answer is that there was a huge amount of corrosion at the roots of the DC to DC IC pins, which was the reason for the voltage drop.

If you want to read fix power supply LA32D403E2, click here.

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