How can i solve or troubleshoot my jvc 21 inch tv?only a line horizontal is present..i suspected it the problem is in the vecrtical ic but how can i assure that and what are the symptoms of a cracked ic?in vertical ic it is craked .

If thhe ic has a crak that you can see then it is no good replace the ic If looks good then look real close where it is soluder ontothe board for little crakes in the soluder where the pins are. I would resolder the ic anyway becouse some thime you cannot see the crakes but the pins are loose. Now there is some capasistors in that cerit also that go bad.You would ned a capasistor checking machine to check these out of cerit.These capasistors that im talking about are usley black with writeing on the side like 10u 25 v this is not for the ones you have in your set just trying to let you know what im talking about. There is a pos and neg side to this kind of cap and they have to be put in just the way they are took out. Try resoludering the ic first then see what happens if it looks ok, if that does not fix it replace the ic and caps. This ic will be mounted to a heatsink by the way.