1/4 of the display appears lines stretch vertically on top

[abayni]

I have a ProView 772 17" CRT. My problem had started last last week while I'm in the middle of work. The display on top of the screen was about 1/4 part of it vertically become broken lines stretching. I tried to fix certain components that are might be a lost contact, but the problem still the same when I power it on. Can you help me trace the possible defective components? I am not a professional electronic tech. Can you help me please?