Problem In LED TV Backlight Modification
A customer sent to me this 32″ Innovex LED TV with the complaint of No Display but the sound were good. The power LED also lighted up. This kind of problem usually indicate backlight fault because the sound were present.
Once the TV cover was removed, the first thing I checked was the LED backlight. I used the LED TV Backlight tester to test on the backlight. For the LED TV Backlight, after you have turned On the device, it will show 300VDC. For a good LED TV backlight, it will show DC volt and the voltage is depends on how big the TV is.
But in this case, eventhough I have placed my probes to check on the LED TV backlight, it still showed 300 volt! This means the LED TV backlight have an open connection and need to dismantle the panel to check on the internal LED TV backlight.
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Once the panel parts were removed I saw someone had done a modification on it.
It was badly done by the previous repair technician and you can check on the two photos below:
Next, what I did was to replace all the internal LED backlight since I have the parts.
After replacement with the new LED TV backlight and Powered On,
I was happy to see all the LEDs were lighted up without shutting down.
I assembled everything back and take a look at the two photos below:
Conclusion- You need to invest on the test equipment that is relevant to your job. Just imagine if I don’t have the LED TV backlight tester, I may be in the guessing game and guessing game usually will take lots of your precious time because you do not know if a particular component is good or bad. If you wish to learn more repair tips and tricks about LCD/LED/OLED TV Repair you can check out on Kent’s ebooks here.
This article was prepared for you by Suranga Bandara who owns an Electronics repair shop in Anuradapura, Sri Lanka.
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Note: You may check out his previous post about How To Repair LG LCD TV With No Power Symptom
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Albert van Bemmelen
July 5, 2021 at 6:15 pm
Like you said it is never about guessing but about knowledge on how to fix a problem. And it also helps having the right tools for the job. Thanks for sharing.
Parasuraman S
July 5, 2021 at 6:20 pm
A professional approach and solution. Well done and thanks for sharing!
Lee
July 6, 2021 at 8:49 pm
Hi,
Thanks for this repair article.
If no LED tester on hand,
can you check/verify each LED by applying 3V or 6V voltage?
Is this approach enough to find a problem?
Frank John
July 7, 2021 at 1:09 pm
This is indeed a very great article, thanks so much for sharing with us. This LED TV back-light tester is a very handy tool and a must-have tool in LED TV repairs, how much does it cost to own one? So when the LED TV sound is okay but no display the main culprit should be the back lighting right, what about the screen itself, how do we identify a faulty LED TV screen/panel?
Yogesh Panchal
July 7, 2021 at 5:36 pm
Good JOb! Suranga
Thilak Kumara Gamage
July 12, 2021 at 1:36 am
Hello, Suranga, I am from Galle I have innovex 32 same TV . Only power LED lighted up no display and sounds .
Please advise me to repair it.
Thankyou,
Thilak
Humberto
July 13, 2021 at 10:06 pm
Good job Suranga