Longer Time To Get On In LG CRT TV Solved
MAKE AND MODEL: LG 21FU3AG3AZ CRT TV
PROBLEM REPORTED: Takes longer time to get on. But remains ok after that.
TROUBLESHOOTING AND RECTIFICATION DONE: After opening and doing a thorough cleaning of the TV, dismantled the board after discharging the anode. On inspection of the PCB, I found a lot of dry solders. ESR of most of the capacitors in power supply and elsewhere were out of range. After replacing all the electrolytic capacitors on the board, and doing a thorough retouching of all the points, connected a 100W load to B+, removing its path to primary of FBT. The bulb lit and voltage was stable and present. Tried switching it on and off a few times and noticed that there was no delay.
Disconnected the load of Bulb, connected the B+ jumper wire to the FBT, reconnected the yoke, degaussing coil, speakers and Video-Audio input board after applying a drop of switch cleaning oil in each and every socket. Applied power and found the TV to be working very well. Adjusted the Focus and Screen Voltages for a peak performance. I was very happy to see the result of the laborious task of retouching the board and replacing all the electrolytic capacitors, which is something I really love to do! Replaced the batteries in the Remote Control. Mission accomplished and satisfaction got added!
HERE ARE A FEW PICTURES:
This article was prepared for you by Parasuraman Subramanian from India. He is 70 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/open-run-dc-resistor-caused-power-supply-failure-in-dvd-player/
Lynn Blakely
July 24, 2020 at 10:26 pm
Another Job well done, Parasuraman. You must stock a lot of capacitors to do a complete cap replacement of all the caps on the board. That certainly completely eliminates, most call backs.
Parasuraman S
July 25, 2020 at 6:10 am
Yes, I do stock of almost all components generally required, as I attend to my work very early in the morning. It is an annoyance that we do not have the required component whenever we set our mind to solve a problem. Moreover, due to pandemic conditions and containment, shops are not open for weeks, nowadays!
Albert van Bemmelen
July 25, 2020 at 12:09 am
Indeed another great done repair after the laborious job of retouching the board and replacing all the electrolytic capacitors! I take it that you measured all those e-caps in-circuit before you replaced the bad ones? Or only those that weren't placed in parallel with other e-caps?
Parasuraman S
July 28, 2020 at 7:20 am
I measure important capacitors especially in the power supply tracks. If I find many of them are reading bad ESR values, I just go ahead and replace the entire lot. I do take the customer's consent to do it, as cost is involved in such an exercise. Thanks for your comments!
Humberto
July 25, 2020 at 12:30 am
Hi Parasuraman, I see you enjoy replacing all the e-caps, but finally you obtain the expected result. Congratulations.
Parasuraman S
July 28, 2020 at 7:21 am
Many thanks!
edward a gamard III
July 25, 2020 at 12:44 am
What does FBT stand for?
Nigel Simeon
July 25, 2020 at 3:26 pm
Fly Back Transformer
A L PANDIT
July 25, 2020 at 6:36 pm
FBT means Flyback transformer also known as line output transformer(LOT).
Parasuraman S
July 29, 2020 at 7:50 am
I had already given full form of this many times in the past. So didn't repeat for the sake of brevity!
Waleed Rishmawi
July 25, 2020 at 2:49 am
Man you replaced a lot of capacitors, I hope the cost of parts and the repair was worth it.
Parasuraman S
July 27, 2020 at 11:00 pm
Yes, of course!
Saqib Sami
July 27, 2020 at 10:30 pm
How to discharge the anode ? Which switch cleaning oil you have used?
Parasuraman S
July 27, 2020 at 10:59 pm
Remove power plug. Wait for a few minutes, hold a thick screwdriver on its insulated portion, ground the metal part to the CRT ground wire, carefully insert screwdriver tip inside the anode cap. Take care, wear a non conducting footwear always.
I used Armstrong Switch cleaning oil.
Saqib Sami
July 30, 2020 at 2:10 am
Thanks for guidance Sir.
Joven Urbano
July 31, 2020 at 2:13 am
Wow, it must take a lot of patience to remove and test all of those parts. Well done!
Parasuraman S
August 1, 2020 at 12:20 pm
When you love what you do, patience automatically comes in!
Yogesh Panchal
July 31, 2020 at 11:06 pm
Revived TV for next 10 Years! Ha Ha Ha............
Parasuraman S
August 1, 2020 at 12:21 pm
Yes, unless natural calamities or high voltage fluctuations cause damages!
Raj
August 5, 2020 at 10:10 pm
Super.. Great learnings.. Thanks
Gary Gemmell
October 16, 2020 at 9:52 am
Consummate repairs to 101% with even the remote batteries replaced - you do not see work of this calibre in the UK - Wow!!!!
Asanka pubudu
July 10, 2021 at 10:21 am
Please tell me a LG 21FS4RGE-TX CRT model Flyback number ...