LED TV Repair- Cheap Replacement Parts
The complaint of this Changhong LED Screen TV was no display (no picture) and in standby mode (red color LED light). The usual problem for a standby LED can be due to bad mainboard or power supply whether it is from Samsung, Philips, Vizio, Pnasonic, Toshiba, Sony, LG, Sharp or Coby brand. The mainboard must receive a stable standby 5 volt from the power supply in order for the MCU and memory ICs to work. If without the 5 volt, the mainboard is totally dead.
If the 5 volt dc supply is improper or unstable, the MCU IC will not send an On signal to turn on the full power and the standby light will remain red and will not turn to green or white. Sometimes the power LED will have flashing light too. So the first thing you need to check is to make sure the power supply is producing a good and stable 5 volt dc supply. As usual, in order to troubleshoot the circuit board, one has to open up the set cover. Below is the photo of the mainboard and power supply board once the cover was removed.
Just by looking at the electrolytic capacitors on the power supply board, we can know that these capacitors were causing the standby problems. It was not one capacitor bulged but 4 of them! Look at the two photos below:
I did not even measure the standby 5 volt voltage because from experience, I can tell that the cause of the problem was surely these bulged capacitors. Replacing these parts was easy, just solder out the capacitors and replace with the same value of capacitance, same voltage and same temperature. These capacitors does not cost much and many times you can use a salvaged capacitors from a junk board.
Just make sure those capacitors are the branded one so that it will have a longer live span as compare to those non branded capacitors which do not last especially working under hot environment. I have tested other capacitors in the power supply and all seems to be within spec so I never replace them.
Once the capacitors were replaced and powered On, the blue screen immediately appeared which prove that indeed it was just the capacitors problem only. It was an easy job and I have earned some profits from this 25 minutes work. Please give me a like in the below if you found this article useful. Thank you.
This article was prepared for you by Suranga Bandara who owns an Electronics shop in Anuradapura, Sri Lanka.
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Note: You may check out his previous repair article in the below link:
https://jestineyong.com/power-ic-and-zener-diode-shorted-in-dvd-player-repaired/
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joopc
June 29, 2016 at 3:57 pm
thank for nice articles
masoud
August 27, 2016 at 1:50 pm
I'm wonder that any body dose'n repair a multiple symptons !!! only capacitors or only an ic must be change/ but in real trouble shooting rarely hapend that only capacitores bulged...
please share very difficult of your experiinses...
Tito Kanshulu
June 29, 2016 at 4:16 pm
Very good work,Suranga,and well explained.
Robert Calk
June 29, 2016 at 6:58 pm
Good job, Suranga. Those easy fixes are sometimes a welcome sight.
Albert van Bemmelen
June 29, 2016 at 8:46 pm
Thank you Suranga. Same problem as with defect Monitors most of the time.
Parasuraman S
June 29, 2016 at 9:03 pm
Good Job! All the best!
maurice chidawe
June 29, 2016 at 9:40 pm
vry helpf. thank you
biruk aweke
June 29, 2016 at 9:50 pm
U are great thanks for sharing.
Victor Mash
June 30, 2016 at 3:54 am
Dats very interesting suranga well done and keep it up.
John Peplau
June 30, 2016 at 8:48 am
As always. Quick, useful, accurate, information aided with the usual, excellent photos. Very valuable information to keep on hand as always. Hats off to all who made this article a winner.
Humberto
June 30, 2016 at 10:22 pm
Good repair Suranga, bad quality capacitors are always doing a bad role in the Electronic Circuits.
suranga bandara, Suranga Electronics
July 1, 2016 at 3:13 pm
Hi All,
Thanks ! so much for your Comments.
Yogesh Panchal
July 1, 2016 at 8:10 pm
suranga,
Good job! bro.
Ehsan Murad
July 3, 2016 at 11:59 am
Very useful since I have the exact same TV.If my has this problem I will know what to do.Thanks
macdonald makwemba
July 4, 2016 at 10:46 pm
well done good job.
sadasivam
July 5, 2016 at 9:53 pm
Good Keep Going
CHAMINDAJ
July 6, 2016 at 5:44 pm
Very Useful Thanks For Sharing
ombra32
July 8, 2016 at 7:14 pm
Good job, many thanks!!
julius
July 9, 2016 at 2:10 pm
Good job suranga your comment is very helpful,and keep it up.
Kishor
August 26, 2016 at 8:14 am
MODEL24D2000C HAIER TVLED POWER OFF AND ON EVERY 5M NO ST ON TV
Noel Gervais Gerard Louis
January 29, 2017 at 12:57 am
Thanks for sharing, I appreciate that.
Lewis Spedding
February 2, 2017 at 8:18 pm
Very well explained Suranga You really have some great repair articles.
Aphiwe
March 18, 2017 at 5:41 pm
This is very useful. Thanks Suranga.