But,Someone say this is a problem of FBT(fly back transformer) or sometime,dry joints(broken soldering points).
Yes, it could be due to those reasons. In addition to that it could be sue to Horizontal/Vertical control ICs as well. I'm sure a TV technician will be able to suggest you a solution. But before making, make sure you ask him to quote you the price, so you can decide.
i think,i can try solve this problem.
I don't think this is a good idea. It is too dangerous to touch without knowing what exactly you are doing. TV technicians know these. Sinhalese saying: When the plier is there, why do you want to burn your hand
However,i must buy a new LCD monitor...
You can buy a used branded (Dell / HP) 17" LCD monitor for about Rs. 8,000 - 10,000. May be even less. I'm a bit biased to those branded stuff even those are used.