How to Fix TCL L40S6500 Panel Problem

How to Fix TCL L40S6500 Panel Problem – Picture Disappears After Few Seconds Due to short circuit V-Com area, Repaired Successfully

A TCL model number L40S6500 came to me for repair. The customer said that we were watching TV when suddenly its picture disappeared. I looked at the TV and turned it on and saw that its picture was on for a few seconds, meaning the logo was only showing and the picture was disappearing, meaning the panel was not displaying. After that, at first glance, I thought it was a panel fault. However, I told the customer to leave it alone. I will diagnose its fault and then contact you. I will tell you what the problem is and whether the upcast will come. This customer is my old customer, and thank God that all my customers trust me. He said that it is fine; you keep it and let me fix it. I booked this TV and gave the customer two to three days time. I said that after that I will call you, and we will diagnose this fault step by step in this article.

Physical instruction 

I opened this TCL LED TV in my workshop lab and started its physical inspection. I started with the motherboard to see what its condition was. There was a lot of dust on it. I cleaned it. There was a lot of dust. I cleaned it. After that, I inspected each part very carefully. I saw what condition it was in. What condition was the PCB in? Is there any rust on it? Despite a lot of dust, there was no rust on its PCB. After that, I looked at the panel. I looked carefully at its scalar strip to see if there was any park anywhere. I carefully inspected the power supply. I saw that there was no spark in them. They were all fine. I also checked all the ceramic capacitors installed in the scalar stick with a magnifying glass without looking at them to see if there was any spark in them. I did not see anything at all in these capacitors that I found suspicious, so I decided to move on to the next stage, which is voltage testing.

Panel Voltage Testing – TCL L40S6500

First I checked the 12 volts in the scalar strip of this panel; it was there. Then I checked the 3.3 volts of the panel; they were also there. Then I checked the AVDD voltage; this voltage used to go off after a few seconds. From this I realized that there was some short circuit due to which the DC was removed in protection mode, which was supposed to take the DC to DC. Switched the set and started checking the short circuit in the scalar strip, then I checked the short circuit step by step. First I checked the AVDD line; there was no short circuit in it. Then I checked its VGL and VGH lines; there was no short circuit, because its scalar strip consists of two parts, a large part that contains the DC to DC circuit and a small part that only contains the source COF and nothing else, so I separated them and saw that the images on one side of the panel were normal, which meant that the fault was in the small scalar strip.

Faulty Capacitor Found on Scalar Strip – TCL L40S6500

I reconnected the scalar strip connection and turned the TV on, and now my attention was on the small scalar strip part to see what was wrong with it. Since the TV was running for a few seconds and during that time I had to catch its short circuit, the method I used to catch this short circuit was to turn the TV on for a short time and then turn it off again for a short time in the same way two or three times. After turning the TV off, I checked the capacitors on the scalar strip and the ceramic capacitors, and I found a capacitor short circuit in them. This capacitor was connected to V-COM volts, and the chassis number of this capacitor was CD1, and it was hot. When I turned the TV on, it was a capacitor that was hot, and after a while, when I turned the TV off, the short circuit in this capacitor was gone. That is, when current started flowing in it, it There was a short circuit, so it was a V-com short circuit. I replaced the capacitor, and my TV was fixed. The short circuit cleared, and both my left and right sides started giving a perfect picture.

• 🔧 Fault Diagnosis Summary – TCL L40S6500
• Reconnected Scalar Strip to begin inspection of the panel section.
• Observed a picture dropout after a few seconds of power on – suspected short circuit.
• Used power-cycling method (on-off-on) to identify the faulty component.
• Detected a hot ceramic capacitor (Chassis No. CD1) linked to V-COM volts.
• Short circuit was confirmed in the capacitor during active voltage flow.
• Replaced the faulty capacitor, which resolved the issue completely.
• Left and right sides of the screen started displaying a perfect picture again.

Conclusion 

You saw how we solved the panel problem in this case. Short circuit in the panel is a common problem. It is a common issue. To solve it, it requires extreme care. You should go to the exact place and remove the short circuit and there should be no further disturbance in the circuit. This should also be kept in mind. Every technician should be very careful in the case of short circuit and should not be in a hurry. In this case, such matters should be looked at calmly and with preparation. I have published an article before that, that was also on short circuit. I will share its link in this article. In my opinion, that was also a very difficult and wonderful job that I did and shared. I am sharing this fault finding article to help technicians so that if anyone gets any help from what I have written or from my pictures, it will be a big deal for me. You will definitely read my second article as well. You will get to learn a lot from it.  Since

Q1: The common question is why such short-circuiting occurs in the panel.

A1: The environment is very influential in such cases; if there is a hostile environment, it creates a short circuit in the panel very quickly.

A2: In my opinion, sometimes because there are so many ceramic capacitors installed in the panel, if one of them shows leakage or a short circuit, it is not unusual. It is a common thing in electronics.

“If you’re interested in a similar short circuit issue on a Samsung LED TV, click here to read that repair article.”

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