How to Fix Water Damaged Screen on Samsung UA40N5300AR TV | V-com Short Circuit Repaired Step-by-Step
I have a Samsung LED TV UA40N5300AR for repair in the workshop. This set was water damaged, due to which the picture was not being displayed; the screen was completely blank. This customer was an old acquaintance of mine. He said that this set was installed under the air conditioner, so water had fallen on it. I physically saw it on its screen. I could see a watermark on the screen. When I plugged in the set, the screen was completely blank, the sound was ok, and the backlight at the bottom was working. I asked the customer for some time. He said, “Okay, you can troubleshoot it and let me know.
Physically inspection
This Samsung model uses an Innolux panel v400hj6-pe1, and the scalar strip of this panel consists of two parts. This was a case of water damage, so obviously I had to examine it closely. I looked carefully at its scalar strip to see if there was any sparking due to water damage. Or is there a source COF it being damaged due to water? I didn’t see anything like that. I looked at it very carefully, but apparently I didn’t see any fault in it visually. I separated its panel from the frame and looked very closely at where the water drops had come from on the screen and where they were visible.
DC to DC Testing
I re-fitted the panel into the frame and started checking its DC-to-DC voltage. First I checked its 12-volt VCC power supply, which was coming, and then I checked its 3.3 volts, and they were also there. After that, I checked its AVDD voltage and found that this voltage would come for a short while, and after a short time, this voltage would go away. Similarly, I checked its VGH and VGL voltages; they also came on for a very short time and then went silent, meaning its DC-to-DC IC was tripping for some reason and protection was being activated. Now the reason is obvious: it could be a short circuit, and now I had to find where these four circuits are. In the next paragraph, we will check the short circuit.
Short Circuit Tracing in Samsung Panel
Now I started checking for short circuits, so first I checked the AVDD line; there was no short circuit on this line. Then I tested the VGH line; there was no short circuit here either. After that, I checked the shortage on the VGL line, and it was also fine. I started checking each capacitor on the scalar strip and found a 15-ohm short on one of them. I checked which line this capacitor is connected to and found that it is a capacitor connected to V-com voltage. I opened the capacitor, but the short circuit remained. Since these V-com line go to every source COF, tracing them is a very difficult task.
V-com Short Circuit Tracing
Tracing the V-com line is quite difficult because this line goes to every source COF. Well, now we know that there is a short circuit on the V-com line with 15 ohms to ground, and we have to find this short circuit, so I am explaining here the method I used to remove this short circuit. I checked this line on each source COF with a multimeter and marked the COF where I found the lowest resistance. When my faulty source COF was finalized, I cut the three tracks going to it, and the short circuit was gone. Now I turned on the panel and looked at it, and my panel started giving pictures.
White Screen Issue After Short Circuit Repair
By eliminating the short circuit of this source COF, the panel turned on, but the horizontal strip of this entire COF area had a lot of whiteness because the V-com voltage was not being supplied to this source COF. It was now necessary for me to further investigate the points where I had cut and eliminated the short circuit so that I could get to the root of the fault. Since this set was water damaged, a spark had formed in the PCB of its terminals between the V-com voltage and ground.
Remove PCB shortage
I decided to take a risk. There was a short circuit in the PCB at the source. I drilled there so that the short circuit would be eliminated and I could bypass the V-com voltage and give it to the source COF. So I took a very fine drill and made it even finer, and with that I drilled a hole in this PCB to eliminate the short circuit. This was such a delicate and sensitive task that if there had been even the slightest mistake, the drill would have damaged the coffin. So friends, the thing is that I adjusted it very carefully and successfully, and my set, that is, my panel, became 100 percent OK.
- Fault: Blank Image on Screen
- Cause: Panel Water Damage Identified
- Issue: V-com Line Short Circuit Detected
- Diagnosis: V-com Hole Connection Caused Internal PCB Short
- Solution: PCB Internal Short Circuit Repaired Successfully
Conclusion
So, my dear friends and my dear technician, this was a water damage fault that I fixed. You saw how I fixed it. Basically, its PCB was damaged, which I repaired. And I did this form successfully; the panel gave a 100 percent result, and the same thing happens when you work so hard. If you are sincere with your work and work hard, then you will definitely get the reward of your hard work. Success will surely kiss your feet. Just keep your intentions pure and work hard on any task. I have also shared pictures in this article so you can see the level of effort this is. I hope you will like my article and you will share it with others so that others can also benefit.
FAQs- Why is water damage dangerous for LED TVs?
Water damage is a very dangerous situation for an LED TV. If your device is running, it could completely damage it. Any part where water falls will damage that area because your TV was running and there was voltage in it, which can cause a lot of damage.
The second scenario is that water got into your LED TV, but it was turned off. You realized that water had gotten into it, so you should show it to the technician immediately. You shouldn’t have turned it on. Show it to a good technician immediately. He will dry it first, and then he will check, assess the damage, or whatever he thinks is appropriate. This can save you money.
If you want to explore more repair articles like this one, click here read our related posts.
Shaukat Ali
Shaukat Ali is a professional Sony LED TV repair technician with over 30 years of experience. He specializes in diagnosing and fixing complex display and board-level faults. Based in Lahore, he shares real-world repair cases to help both customers and fellow technicians.