Backlight Replacement In 42” LG LED TV MODEL 42LF550T
This 42” LG LED TV was brought to me by a customer living in another town. He had heard about me through some of his friends and contacted me first to get his old Philips Valve Radio for repair. But I had put him on hold for the last one year, as I was unable to finish the backlogs, in between of which the Corona Pandemic social control came in vogue. After the scene was more or less clear, he spoke to me again saying that his TV was also dead and preferred to bring these two to me. So, I had to yield to his request and thus this TV landed on my table. When I switched it on, I noticed that there was no display, though the set was getting on. I opened the back cover, did a cleaning job.
Then when checked in power on, the LED driver was delivering the output, but the light was not getting on. The customer indicated that some loose particles were running around inside the TV, when the TV was transported, which in itself was an indication that the LED domes would have fallen loose inside. So, dismantled the set and removed the panel to get access to back light. The Panel with its sheets underneath were held together while removing and transporting it to a safe place for keeping. This has to be handled very carefully, lest it should get damaged or cracked by either hitting on the walls or doors. After removing the reflector, from its holding clips, I saw loose domes of LED and found one LED burnt.
I used one of the kitchen knives, which was ground to half and sharpened at the tip to cut and take out coconut kernel. This was a handy tool in removing LED strips very easily. Fetched replacement LED strips and stuck these in place observing A and B positions. Did test the new LEDs using the Tester.
After fixing the backlights in its place, I reassembled the TV and applied power and was delighted to see the TV working very well! Run the TV for several hours and found it to be working very well. Then called the customer, who came and picked it up promptly. Satisfaction got gathered to its collection bag without fail!
This article was prepared for you by Parasuraman Subramanian from India. He is 72 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.
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You may check on his previous repair article below:
https://jestineyong.com/burst-pwm-ic-and-caps-found-in-panasonic-dvd-player/
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Mihai
April 10, 2021 at 12:18 pm
Hello , Good job sir !
You make the customers happy.
Parasuraman S
April 10, 2021 at 4:19 pm
Many thanks!
Albert van Bemmelen
April 10, 2021 at 2:00 pm
You are a busy man and not afraid to handle the more difficult repair tasks like fixing this larger LG Led tv. And always seem to have the right spare parts at hand, like here the A and B led strips. The mirrored image in the LCD tv on the photo this time now also showed us a small peek into your repair room, and the Sherlock screen after that is of course your usual trade mark!
Parasuraman S
April 10, 2021 at 4:21 pm
You also seem to be as shrewd as Sherlock Homes in observing minute details! Many thanks!
Yogesh Panchal
April 10, 2021 at 4:27 pm
Good Repair Sir,
Parasuraman S
April 11, 2021 at 1:45 pm
Many thanks, Yogesh!
Waleed Rishmawi
April 11, 2021 at 9:49 pm
Thanks for sharing this repair job with us. I stopped working on such issues due to the fact I can find replacement parts. Many technicians repair only the burnt part by adding a short which not very affective.
Parasuraman S
April 12, 2021 at 2:24 pm
Many thanks for your experienced comments!
Humberto
April 14, 2021 at 3:46 am
Great repair. Congrats.
Parasuraman Subramanian
April 15, 2021 at 4:49 pm
Many thanks!