Television and Home Theater

Our new TV has static-like cracks when we turn on a light switch or the dishwasher, etc. It also makes the cracking sound when we get up from the sofa like we are making static. Usually only the sound and not the picture are affected. Will this shorten the life of my TV? Is there anything I can do to stop it?

When watching the TV, it would shut down and sometimes the picture would darken and roll diagonally.  It could not be turned back on using the remote.  I would have to use the main power button behind the flip-down panel below the screen.  Once when I powered it back on a yellow Y appeared in the center of the screen.

I had the convergence repiared on this TV in May 06. At the time the red was out of whack. The repair guy replaced parts on the board and all was well. Now I am noticing that I am getting a blue halo aroung white objects and in some dark scenes. I tried to run perfect focus but it gets stuck when it gets to blue. When I go into manual convergence mode, it appears that the crosshairs are lined up for both the red and blue. I have not tried to manually adjust either. My question is: do you think my blue convergence is starting to go bad now? Should I have the board repaired again?