Picture problems are surely among the most common technical issues experienced by home TV viewers. Such problems may manifest themselves as pixelization or frozen pictures, intermittently flashing pictures on one or more channels, static or audio degradation, or channels that are missing altogether. To address these problems, you can always contact the technical support department of your cable TV provider and have them walk you through troubleshooting steps, but it is wise to learn how to fix problems like this on your own without consulting any outside help. Doing so can save you lots of valuable time and money in the long run.
Reset your cable TV equipment by unplugging the power cords of any digital cable boxes/DVRs you use in the home. Count a full 30 seconds and plug the equipment back in. After allowing the device enough time to complete its boot cycle, check the picture again for any improvement. A cable box in need of a reset is by far one of the most common causes of many different picture degradations, so this is a necessary first step.
Check the audio/video connection cable or cables that attach your cable service equipment to your TV. Loose or malfunctioning cables are also a very common cause of picture degradation. Secure any cables that may have come loose and replace any visibly damaged cables. If you think the cables may be failing, you can temporarily test them by plugging another audio/video connection cable from the cable equipment to the TV and checking for any improvement.
Scan through your entire channel lineup as well as all the input channels on your TV. This will help determine the scope of the problem and how to most effectively troubleshoot the issue further. If you see the vertical lines on only one or a few cable channels, the issue is much more likely with the broadcaster or your cable provider, and you will need to report the issue to your provider. If you see the vertical lines on all channels and all video inputs, it is more likely that the TV's picture components are beginning to fail, and you will need to have the TV serviced or replaced altogether.