The main problem with this TV set was, there is picture but there are lines across the screen. From experience, this kind of problem is caused by bad capacitors in the set. With ESR meter, I checked all the capacitors in the power supply, primary and secondary but all checked within specifications.

I checked the voltages reaching the HOT and it was ok and steady. To be on the safe side, I also checked all the capacitors in the high voltage area but again, they checked ok in that area as well. My focus was shifted on the vertical section which should have been in the first place. I checked all of the capacitors there and they all checked ok. It was really strange because I mainly checked all the capacitors in this TV and I cannot find the fault in it yet I see the fault on the screen with all these white lines.

This time, I wanted to use a different method of finding this fault. May be something was getting bad when the load is there but check ok when the load is not there. So I turned the set on and I started checking with a cold spray. I sprayed all the capacitors in the power section, and nothing happened but when I sprayed a capacitor near the vertical IC something happened. The lines disappeared for a moment then they came back. It was a 2.2uf/50 volt capacitor that I did not check before with the ESR meter since it was tiny and was hiding in the other side of the vertical IC and simply I could not see it. I replaced the capacitor and the picture was restored and it actually looked good for a Chinese made TV.

Conclusion: I thought I checked all the capacitors but I did not. Always look and make sure you check everything otherwise, it will cost you time and effort. The cold air is very good method for checking capacitors especially when the capacitors get hot when they are charged. It worked for me and I was happy about it.

About

10 years of practical electronics. owner and operator. I service the Bethlehem area in Palestine. I repair Xbox 360 and all play stations and modify their power supplies. also repair lcd and Plasma tv sets, and lcd computer monitors. I have a degree from Bob Jones University in general business and one year degree in Industrial electronics. a intensive course in Media. I also work as a camera and audio man as a free lancer. Also great experience in video editing and installing surround systems for home and movie theaters.

Leave a Reply

Your email address will not be published. Required fields are marked *