Tv problem. Will connecting component video cables to the tv and dvd player while still beiong

Question

Will connecting component video cables to the tv and dvd player while still beiong turned on damage the colours of the picture. Not long after owning a new tv set, i discovered that there seems to be dimming effects on the picture. Picture dims when a scene changes from one to another and the background appears darkened. Some scenes look perfectly normal until they change to another . Is this what you call phospor burn. I can tell you for sure it isnt colour shading due to changing the direction of the tv as the problem has gone on for weeks. I tried the local channels, the satellite channels and dvd playback and they all display similar symptoms. What are the possible causes and what can i do without sending it to the repairmen. Your help is much sought after. Thank you.