Many problems with a cable TV picture can be easily fixed by the cable subscriber.
The cable signal on your TV is delivered from the cable company headend through a trunk cable to your neighborhood, where it is amplified and distributed in individual drops to cable subscribers. Signal degradation along that path is the responsibility of your cable company. Your cable company can diagnose and fix a poor-quality cable TV picture due to problems inside your home as well, though a costly service call may be required. You can avoid that cost if you check and fix the common issues that cause a low-quality cable TV picture.
1. Check the cable connection on your TV or cable box to ensure that it is tight. Check the connection at the wall jack and ensure that it is also tight. Unscrew the cable from both the TV or cable box and the wall and examine the connector. Ensure that the center pin is straight. Examine the cable for damage to the outer casing. If damaged, replace the cable with another piece of similar length.
2. Shorten the cable from the wall jack to your TV. A cable signal degrades as it passes through coaxial cable. A short cable will degrade the signal less than a longer cable. Replace a long cable with a shorter one. Consider moving the television closer to the wall jack to keep the cable length short.
3. Replace cable couplers with inline signal boosters. Standard couplers that connect two pieces of coaxial cable cause signal degradation. Inline signal boosters do not require power and ensure the integrity of the cable signal as it passes from one piece of cable to another.
4. Replace cable splitters with powered signal boosters. If your television is attached to coaxial cable that connects to a splitter with another TV, DVD/VCR and/or cable modem, the signal is divided among all the devices. A powered cable signal booster will compensate for the split signal and amplify the signal to all devices.
5. Add a powered signal booster to the cable between the wall jack and your television. Powered signal boosters boost the signal by 15-20 decibels. If you need to boost your cable TV picture because of poor connectivity, loose connections or damaged cable in the walls between the drop and the wall jack, a powered signal booster can amplify the signal and compensate for any signal loss.