High-definition televisions (HDTV) of any variety -- plasma, 3D, DLP, projection -- can offer unrivaled picture and sound quality and completely remake your home entertainment experience. Like all other consumer electronic devices, however, HDTVs are not immune from certain technical problems and malfunctions. It is always preferable to troubleshoot them on your own and luckily even the most advanced of plasma screen TVs require just a few simple techniques.
Physical Connection Issues
Probably the most common cause of vertical or horizontal lines on the TV screen is a loose or malfunctioning physical connection that attaches the device you are trying to watch to the plasma TV itself.
For instance, if you notice lines on the screen when watching a DVD player, locate the audio/video connection cables (HDMI, S-video, RCA, component, or other type) that attach the back of the DVD player to the input connection ports on the plasma TV. Remove the cable or cables and check the tips for damage, bending, or dust or moisture buildup. Clean any dirty cables and replace any cables that are damaged beyond repair. Firmly plug all connection cables back in and check the picture again for any improvement.
A problem could occur with the picture components of the actual device you are trying to watch. To recall the same example, insert a different DVD disc into the DVD player and check to see if the lines still appear on the screen. If so, try replacing the audio/video connection cables if you haven't already. If there is still no improvement, temporarily connect the DVD player to a different TV in your home and check for any improvements in picture quality.
If the lines appear on the second TV as well, the problem is likely with the DVD player itself and it will need servicing or replacement. If there are no lines on the screen after connecting the DVD player to the other TV, the problem may be with the individual input on the plasma TV. To test this, connect the DVD player to an alternate audio/video input on the TV and check for improvements in picture quality.
Check for a problem with the plasma TV itself. Scan through the other input on the TV using the button labeled "input" or "source" on your plasma TV remote and see if picture quality improves. If it does not, the issue is almost definitely with the TV itself and you will need to have the TV serviced or replaced.
Cable Service Issues
If you only notice lines when watching cable TV service rather than a source device (DVD player, video game system, etc.), another possibility is that your cable TV service provider may be experiencing a service outage or degradation of which you are a part. Determine which channels are displaying the worst picture distortion and check those same channels on your other TVs. If the same channels appear distorted on the other TVs in your home, report the issue to your cable TV provider to check for a possible service outage.