How To Repair LED TV Backlight Problem – No Picture
A customer of mine sent to me this BG LED TV with the complaint of have sound but no picture. This kind of problem usually caused by one of the bad backlight LED in the LED bar.
With just one bad LED, the TV will shut down thus no picture can be seen. Once the cover was opened I could see three circuit boards i.e; the power supply board, main board and T-con board see the photo below:
I then performed the dc voltage check on the LED backlight connector and found that the DC voltage came for a while and shut down. This usually indicates the LED backlight have problem. But I have to open the set in order to proof that I’m correct in saying one of the LED backlight could have problem.
When you are removing the LED TV internal parts be extra careful for the Tab bonding. If you break it then the panel can consider useless unless if you know a way to fix it.
Once the all the LEDs are exposed, you can check each of the LEDs with your meter by setting the meter to diode mode. A good LED should light up and the bad one will not light up. See the three photos below:
True enough I found a bad LED. This is the main cause of the TV shut down. Since I have the LED bar and do not have the single LED thus I replaced the whole LED bar and can keep the remaining good LEDs for future use.
It was a fantastic view when you can see all the LEDs were perfectly lighted.
Once you have confirmed the LEDs were all working fine and no longer shutdown, you can put back all the parts. Connect back the LVDS cables gently to the T-con board as shown below:
The BG LED TV were finally repaired and I was very happy as I could earn some money from this work. If you truly want to venture into LCD or LED TV you can check out on Kent’s and Damon’s Ebooks. Once you have got their ebooks, you can ask for technical support from them to make you a good LCD/LED TV troubleshooter. All the best to you.
This article was prepared for you by Suranga Bandara who owns an Electronics repair shop in Anuradapura, Sri Lanka.
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Albert van Bemmelen
January 3, 2017 at 11:21 pm
Thank you Mr.Suranga. Very professional repair with clear photos and explanation. Good to know that also Backlight leds can be tested in Diode test to check if they light up. Maybe that is also a good reason never to test CMOS ICs with a Digital Meter in Diode/Beep test. And good to know that the reason a LCD TV quits can be caused by a single defective Backlight Led.
suranga Electronics
January 5, 2017 at 2:05 pm
Hi Mr- Albert van,
Thanks So Much for Your Comment,
Jack rogers
April 5, 2017 at 9:01 am
Could you indicate how much the repair cost? I had the same problem. . Took tv to repair shop they said it would cost more to repair than what the tv was worth $6-700 i was suspicious when they said they would keep it and dispose of it as it was worthless Thanks
I
GANESH CH SAHU
January 22, 2018 at 3:48 pm
Sir where to buy led strip
Parasuraman S
January 3, 2017 at 11:53 pm
Very useful service info! I have never ventured to open up an LED TV to this extent! Now, I think I can give it a try! Many thanks!
suranga Electronics
January 5, 2017 at 2:06 pm
Hi Mr,Parasuraman
Ok ok
Thanks You..!
Bulent NUR
January 4, 2017 at 1:03 am
Thanks for sharing, good job.
Randy
January 4, 2017 at 1:51 am
Nice job! But I am somewhat confused by your sentence that you were happy to earn some money from this repair, do you not get paid for the electronics work you do? You have valuable knowledge and skills and should be well paid for your work, I have seen it many times here!
suranga Electronics
January 5, 2017 at 2:08 pm
Thanks Mr- Randy.
Anthony
January 4, 2017 at 2:40 am
Good repair Suranga and it was fortunate that you had the exact same
LED strip that you could use in that tv. Thanks for sharing your articles
here. Kind Regards
zaheedi farjan
January 4, 2017 at 2:40 am
Great awesome i have learn more thank u sir i have a question i got lately a 32 inch sony bravia the prob is the image is blurred n
negative no colour plse advise me
Regards
Zaheedi farjan
mahmoud_tajpour
January 4, 2017 at 2:47 am
Hello Bandara really well done.
Mark
January 4, 2017 at 5:59 am
Hey Suranga,
Thanks for your article. I have dealt with similar cases recently in the automotive field, where faults will make the vehicle either shut down or go into 'limp home' mode - a limited system of operation. These were designed to stop over-current of the system and protect the Electronic Control Unit. I guess it is similar with the TV - a protection mode is created.
Well done on your repair.
angelo
January 4, 2017 at 6:40 am
great job sir Suranga
congratz
keep it up....
Pravin Mevada
January 4, 2017 at 8:09 am
now some led for back light 6 volt which not glow with diode test I suggest test led tester is best for single or hole back light Thanks,
Robert Calk
January 4, 2017 at 12:07 pm
Thanks Suranga. Nice work.
Yogesh Panchal
January 4, 2017 at 3:03 pm
Suranga, Good job! keep up Sharing.
Tito Kanshulu
January 4, 2017 at 4:40 pm
Good work Suranga.
Humberto
January 14, 2017 at 12:11 am
Suranga, great repair and very good explanations.
Chris
January 22, 2017 at 10:07 pm
Hi Mr.Suranga, you are a very high skilled service person in the field of
audio and tv repairing.
You share also very interesting information's with as and that are very valuable for persons who deals with such repairing as you do.
I can say, hats of and look forward with the upcoming modern technology.
Be between the best pros as you like now too.
My best regards.
CAIN
February 7, 2017 at 7:25 pm
FANTASTIC VERY INTERESTING INDEED I ENJOYED IT AND ALREADY REPAIRED MORE THAN 10 LEDS AND MADE SOME MONEY MY CHALLENGE IS TO GET THE SPARES HEREB ZIMBABWE
REGARDS
CAIN
Samsudeen
February 20, 2017 at 11:50 am
Dear sir
Every time you give useful information to improve the knowledge about electronics.I am really thanks to you.
reza
April 12, 2017 at 1:15 pm
hi
thank u
Avi
August 6, 2017 at 6:22 am
I have Samsung TV UN75F6300AFXZA back light is gone I don't know what is the actual part number of stripe, there is big confusion
BN96-26413a
BN96-26413B
BN96-26413c
I am not sure which one I buy can someone please help me to solve this problem.
Nimalkantha
October 4, 2017 at 6:01 pm
Thanks.good review
I have question.my 42inch LG 2010 manufactured,slim border
LED has sound but no picture.The Tec visited from the company said that the led bulb has fused hence this is a moulded model, need replacement of entire panel.which is costly.
Is it true.
Please advise
Thanks
kenny
November 20, 2017 at 10:32 pm
Thanks Mr Suranga for the detailed information. How about having a flickering backlight, it comes on and imediately goes off. What is responsible for this
boniface
December 19, 2017 at 10:41 pm
when the TV gets a backlight problem, how does it perform?
logan parumal
January 10, 2018 at 7:33 am
Hi Suranga, thanks for the illustrative explanation. Would have been great if you have included some video clips demonstrating your testing of equipments practically.
Jesse
January 31, 2018 at 10:29 am
Thanks for the info. When you say the LED supply comes on briefly, how long is briefly? I have an LG 42LB5600-UZ that I purchased a power supply for but does the same thing. I see proper voltage from + to chassis, but LED + to - shows nothing. I can see a quick blip at power on no longer than a half a second with an AC voltage measurement of ~100V peak. Does this sound like a bad LED?
Anderson
April 21, 2018 at 8:12 pm
hi Mr Suranga... that info about the LEDs was very helpful... I found one to be faulty in a TV I was attempting to fix... I'm just wondering where I could find spares. all in all may I just say, keep up the good work, your reach goes further than you'd ever know.Anderson.South Africa.
Patricia
January 2, 2019 at 2:25 am
Hi, I have a 55 inch lg 55lb6000-uh that i am having a problem finding the backlights that goes to it. so i was wondering if i can use another model of backlights thats compatible with this tv
Johnny
April 12, 2019 at 10:40 am
Hello.
How do you test the voltage rating of an LED in an LED TV? In online stores, you can buy 3V and 6V SMD LEDs but how do you check the voltage of the LEDs on the TV so you can buy the correct LED replacement?
Thanks.
salim
May 26, 2019 at 10:59 am
That was wonderfull
GOVINDAN
August 25, 2019 at 1:28 am
Sir I have 55uh7700-ub lg tv,the tv power supply light on but no picture black screen.(the power 13 volts ok back light volt each 115 volts)
Paida
November 25, 2019 at 3:56 pm
Thank you with the information, how much do the back lights cost?
Timmy
December 13, 2019 at 6:54 pm
Thank you for this timeless information.
Ratshaka
April 8, 2020 at 8:22 pm
I see this how to repair led,my question is how to repair a led TV that repeately burning led stripe.
Kanake
May 5, 2020 at 1:39 am
Hello jestineyong, please I need your help. How can I trick Sony LED TV 32" to make backlight system work normaly as if backlights are connected so that I modify another system to control backlight?
I would like to avoid mainboard converter since it as fried light several times.
Jestine Yong
May 6, 2020 at 10:50 am
Hi Kanake,
Try check out this link https://jestineyong.com/simple-modification-on-sony-led-tv/
Jestine
Ulises Aguilar pazzan i
November 17, 2020 at 2:47 am
good morning sir
grate fix & information