Sony Crt tv vertical line

My aunt told me that her tv has a one line in the center. So I visited it and it was true that it has one line across the center horizontally and it means I should trouble in vertical section but sometimes it should not be case in other tv . But we should focus first on this Sony crt tv 21 iinch. When I open the tv I go directly to vertical section and check for loose connection and it has I am lucky that is minor trouble. By resoldering it the tv came back to life.