What television interference looks like
Generally with digital television you either have an excellent picture or you have no picture at all. At the threshold point you may notice the picture breaking up into multi-coloured squares of varying screen coverage.
A normal signal should look like this:
The television receiver signal check should look similar to this:
Weak signal and interference
Weak interference or marginal signal levels may look like this:
Moderate interference or weak signal levels may look like this:
Video plays with music in the background that is broken by interference - the interference in the signal gets progressivly worse
Strong interference or very weak signals may look like this:
Severe interference will often result in no picture or a locked picture. Sometimes words like “Bad or No Signal” or “No Service” will be seen on the screen.
At the same time your receiver signal check readings and or television screen may look similar to this:
Television receiver signal check
Television receivers usually have a signal strength and quality analysis screen, normally accessible from Menu > Installation > Signal check or similar (varies between receivers). You can use this to check your signal strength and quality.
If the reading is fair “strength” and poor “quality”, it's likely you have an interference or reception problem of some type. No readings also indicate a problem. You may need expert assistance to determine the nature of the problem.
See What to do about TV reception problems for more information.