static t.v.

hey everyone I have a rca home theatre its about 13-15 years old. It hasnt been used very much untill the past coupld years. the other day i was sitting watching some t.v. and i heard a like boom noise? it wasnt very loud but some weird noise. now my t.v. is very staticy like in the ads on the side of the website. if i change the imput to dvd mode it works like normal but when it is on (with or w/out the time warner cable box on) it is staticy. i dont have any expirence with t.v.'s or anything so if anyone knows a way to fix this id be extremely happy. thanks