Burnt And Badly Leaked Capacitor Found In Samsung CRT TV
MAKE AND MODEL: SAMSUNG CD20F4 CRT TV
COMPLAINT REPORTED: Dead
HISTORY: This CRT TV had come to me with a problem of no video a couple of months ago, which I solved but with minimum maintenance as the customer did not heed to my recommendation of total replacement of all electrolytic capacitors on the board.
TROUBLESHOOTING AND RECTIFICATION DONE: I went to the customer’s house, opened the set and dismantled the PCB and brought it to home. This time, I told the customer that I was going to do a total replacement of all the electrolytic capacitors, which she readily agreed.
My first work was replacing all the electrolytic capacitors. While doing that I came across this 22/160V Cap which had its bottom burnt and leaked. A problem due to over voltage. After I completed the retouch of the board on places which were not covered last time, I disconnected the B+ to the FBT and connected a 100W as load. Checked the voltage and found it to be around 134; i.e., about 9 volts more than the normal. As per guidance given by expert techie friends, I checked one resistor in the SMPS secondary feedback circuit and found that the value had gone high. So, replaced it and found that the voltage was around 125, which is normal. Disconnected and discharged the tank capacitor, reconnected the jumper wire to FBT and loaded it on to my testing CRT Tube. Found raster. But I got some burning smell, which was coming from the PTC of the Degaussing circuit. It was getting hot (another indication that high voltage was the cause for failure). So, replaced that too. Tested the Board by running it on for a few hours. Then discharged the anode and tank capacitor and dismantled the board. Went to the customer’s house, re-fixed the board, switched on, adjusted the screen and focus voltages and fixed the back cover. The TV was found working very well with better clarity and the customer was happy about it. Mission accomplished, money earned twice on this TV along with satisfaction too! Note: Some customers will learn hard lesson only after they burn their fingers! What to do! That’s how they are and we cannot do anything, even though our reputation is at stake due to bad oral publicity!
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/smd-regulator-ic-found-open-in-olsenmark-omr1239/
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Albert van Bemmelen
September 16, 2020 at 12:41 pm
Another phenomenal repair on fixing a troublesome crt tv Parasuraman! The clarity of the screen indeed looks fantastic!
And the fact that you were able to fix the PCB board even without having it attached to the crt is a experienced confident repair engineer at work!
Parasuraman S
September 16, 2020 at 4:48 pm
Many thanks! A lot of encouragement that serves as fuel to surge forward!
Mark
September 16, 2020 at 7:23 pm
Well done Parasuraman!
You truly are the master of the capacitor 🙂
Parasuraman S
September 18, 2020 at 11:07 am
Ha!Ha! Many thanks!
babu ms
September 16, 2020 at 10:19 pm
Sir,
Your really great,since your pouring the capacitor problems in the equipments in your articles. Thank you very much for sharing.
Parasuraman S
September 18, 2020 at 11:07 am
Many thanks!
Yogesh Panchal
September 16, 2020 at 11:03 pm
Perfect Fault finding.
keep up sharing the experience.
Parasuraman S
September 18, 2020 at 11:08 am
Many thanks!
ivan
September 20, 2020 at 4:07 am
Hola señor PARASURAMAN quisiera me explicara cual es la razón de cambiar tantos condensadores Cuéntenos por favor ,que método de lectura y prueba de estos usa y en que medida manifiestan que están dañados En mi pais CHILE Casi la totalidad de los productos que se comercializan provienen de CHINA Y estos al fallar ,no presentan tanto deterioro en condensadores Será la obsolescencia
programada contra LA QUE USTED esta luchando Valoro y agradezco todos los artículos que aparecen gracias a la gentileza del señor JESTINE YONG Reciba UN GRAN SALUDO de un seguidor desde CHILE, SUDAMERICA
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Hello, Mr. PARASURAMAN, I would like you to explain to me what is the reason for changing so many capacitors. Please tell us what method of reading and testing these you use and to what extent they show that they are damaged In my country CHILE Almost all of the products that are marketed come from CHINA And when these fail, they do not show so much deterioration in capacitors It will be obsolescence
programmed against WHICH YOU are fighting Valoro and I appreciate all the articles that appear thanks to the kindness of Mr. JESTINE YONG Receive A GREAT GREETING from a follower from CHILE, SOUTH AMERICA
Parasuraman S
September 22, 2020 at 3:40 pm
Many thanks! I use ESR meter and capacitance meter (after caps are removed). As a routine and part of preventive maintenance, I change all electrolytic capacitors on the board, when I find the readings of many caps are out of range.
Nima
December 29, 2020 at 5:54 pm
Hi sir , i have a 14 inch samsung crt tv , a 160 volt 100 mf capacitor blew up then i replaced it with a new one but now tv doesnt turn on , there is standby led but tv dnot start.
Also there is no 180 volt, 110 volt in secondry side.
In primery side i measure the voltage acrros the tank capacitor i only get 160 volt , capacitor rating is 450 volt , when tv was ok i measured voltage 330 volt but now only 160 volt , please help me.