try doing these if you haven't yet
- try different inputs (HDMI, component, w/e else you have)
- use different cables
- might be your cable box if you have one
- might be a loose connection somewhere
if all else fails, it is either a bad lcd capacitor or the board itself is having problems with making proper connections. from how you described your vertical lines, it could be the TCON (timing and control board) card gone bad. you're better off buying a new tv if you don't feel confident enough to do some soldering.