Backlight LED Domes Found Lying Loose In SONY LED TV Model KLV32EX330
This was referred to by a customer who had his emergency light and torches repaired by me in 2018. The TV was in use by two super senior citizens whose entertainment was only watching the TV. The complaint reported was that the TV remained in red light and was blinking. Though I never visited any houses, I obliged to go and see the complaint as it was near my home and the family was very much known to me. On switching on the TV, the LED turned to green but immediately turned to red and gave 6 blinking codes, which meant that the back light was defective. I told them to transport the TV to my home, which they arranged through an Auto Rikshaw (a three wheeler vehicle available on hire).
As it was an off day for me, I opened the TV immediately and cleaned inside. The TV was powered by a separate adaptor. (19.5V) Saw a couple of dead insects on the board, which luckily did not cause any damages:
The Compo PCB was very sleek and placed very compactly at the bottom. Removing these was not that difficult:
After the scaler board was set free, I removed the front frame and removed the panel and the diffuser and reflector sheets upon which I happened to see a few domes of the LED had come off! I removed the strips one by one sliding it off its holding brackets:
Evidently, the backlight has given a maximum life as it worked from 2013 (See the model label) to 2024! I obtained exact replacement and fixed these in place, which again was very easy. These were 3V LEDs. (8 LEds x 4 strips)
Then put back the sheets and kept panel on top and fixed the frame as how it was before. The LED driver was a unique IC, which was controlled by the uController with a lot of interactions.
The LEDs were fed positive potential commonly and the ground was controlled by the pins (11 to 16) in the IC.
Sony circuits have a lot of protection controls and if the current was drawn in excess of its design, the error is detected and shown by blinking codes. The pin 2 of this IC gives out the fail report to the uController. Normally the concerned pin in the system IC is held high and pulled down when an error amplifier transistor conducts getting the biasing voltage from the fail output of the LED driver IC. I have covered this more in detail in yet another article on a 43” Sony LED backlight issue.
You will perhaps notice that the LED driver with 40 pins handles various functions with interactions to the system IC! Is it not a marvelous design for an LED driver?
Ok, OK, I know some of you might be getting impatient and curious to know what was the end result of my work of backlight replacement! Here it is at-last (Your patience paid (LOL):
I don’t think I had handled the repair work of an LED TV so fast before! Picked up the TV by 9.30AM. Fetching replacement strips and fixing took about 4 hours. The TV was up by afternoon. I allowed it to run for a few hours and delivered the TV to their home in my car and fixed it on their table and played their favourite channels (By 6.30 PM). The customer, who was a retired Professor at her very old age, thanked me profusely. A worthy work for a deserving lady, which added up the intensity of satisfaction that won entry into the collection bag!
I was happy that I could live up to the expectation of my other customer who referred this case to me. It definitely was a good day and I did not forget to thank the God for that!
This article was prepared for you by Parasuraman Subramanian from India. He is 74 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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Waleed Rishmawi
March 29, 2025 at 4:37 pm
good job on the repair. Led replacement usually very easy but the main concern for me is taking the panel off and back on which makes me a very nervus tech and under a lot of presure. have a blessed day
Parasuraman S
March 29, 2025 at 9:05 pm
Many thanks for your comments, dear friend! Yes, it is always a tension for moving out panels and putting it back!
Yogesh Panchal
March 29, 2025 at 4:58 pm
Good JOB! Sir,
DOM fittings are major problem in LED TVs.
Parasuraman S
March 29, 2025 at 9:06 pm
Yes, it is a part of our touch jobs to be undertaken!
Albert van Bemmelen
March 29, 2025 at 5:06 pm
Although you probably know I hardly fix any tv's nevertheless found this article very interesting with good info on the Sony led driver chip and its protection methods.
After their well known famous Trinitron CRT sets Sony was left behind in the modern LCD tv race for a couple of years but I suppose they have packed up quite well since then. Still the bad glued on led diffuser problem keeps coming back in many backlight lit sets.
Parasuraman S
March 29, 2025 at 9:08 pm
Yes, we do get LED backlight problems not only in Sony, but in almost all other brands as well. I think, the manufacturers make it to fail within a few hours of working! But in this case, it was different! However, nowadays, even the device is programmed to fail after the warranty period. Many thanks for your expert comments, dear Albert!
Jason Burgher
March 30, 2025 at 2:20 am
I thank you so so much for the repair info. I get so upset on the waste the USA does. Most of the people have been scared to even open it up. Nobody tries to understand why it broke. Just, quick hurry, run and buy new. Do not worry, just add more debt. I miss the 1980s,in my generation we loved fixing stuff. Thanks again, you really give me hope. We electronic repair guys need to stick together.
Parasuraman S
March 30, 2025 at 9:15 am
There are different cultures in different countries. The more comfort zone you reach, the more care free you become! That growth unfortunately also has side effects such as mentioned by you. Many thanks for your involved comments and sharing your thoughts, poised at working together globally for fighting e-wastes! Our great Jestine yong is a key person who rolls out such fighters almost every week and increasing our population1 Perhaps the future would be favoourable! Let us hope so!
Mark J
March 30, 2025 at 3:08 am
Parasuraman well done on the repair. You are right Sony TV's do have a lot of protection controls.
Parasuraman S
March 30, 2025 at 9:18 am
Yes, dear Mark! Working on Sony TV always is educative! We learn one thing or other always! Many thanks!
Imoudu
March 31, 2025 at 4:52 am
Yes,the Ucontroller ic is very impressive,some Sony tv are heavy in weight though, which usually scare me to repair.Thanking God is commendable,in my country I don't think there is any E- technician at 70 still repairing,they say they are weak and lose of stamina,well I personally wish to still be able to repair at my 70 too my God's grace,thanks for sharing sir.
Parasuraman S
March 31, 2025 at 3:07 pm
Just keep up the good spirit and staunch on your objectives, then there won't be any type of hurdle! Many thanks, dear Imoudu!