Tv has sound but no Picture. i have the LT 42HVi 42" Olevia Tv,and it worked ok,until i plug any

Question

i have the LT 42HVi 42" Olevia Tv,and it worked ok,until i plug any device, like A PS3.when i turn on the PS3, i hear the sounds that are usually heardwhen the console is turned on, and when i use the controller i hear theeffects of it, but there is no sound.also, i don't know if it's a settings problem or something with the TV,because once with different settings it showed the picture, but it was all blue- you could see the PS menu, but it was just shades of blue.how can this be fixed?!thanks,O D