Picture discolouration, one of the more common service problems experienced by TV viewers, typically manifests itself in the form of discolouration, static or pixelization on the screen, or horizontal or vertical bars across the picture. To address this, you can contact the technical support department of your cable provider and have them walk you through some troubleshooting. Many people prefer, however, to learn the same troubleshooting steps that the tech support rep would use and to perform them at home. Doing so can resolve your picture problems without having to consult any outside help.
Reset the TV and any associated digital cable equipment (digital cable box, DVR, TiVo, etc.) that is connected to the TV by unplugging the power cords of each device for 30 seconds and plugging them all back in. After all the devices reboot, check the picture for any improvement.
Tap the coaxial cable that connects your cable jack to either the TV's coaxial input or the coaxial input on your digital cable box/DVR/Tivo. If the picture either improves or degrades further when you tap the cable, the cable itself may be the culprit. Remove the cable and check it for any bending or damage; replace the cable altogether to be sure. Once again, check the picture for any improvement.
Scan through your entire channel line-up to determine the extent of the problem. If all channels have the same black lines, the TV itself is likely at fault and you will need to contact Techwood about having it serviced or replaced, particularly if none of the other TVs in the house show the same black lines. If other TVs in the house have the same symptoms, particularly if they appear on the same channels as on the Techwood TV, it is much more likely that your cable provider or that station itself is experiencing a service outage degradation. Report the issue to your cable provider if this is the case.