Problem with Samsung LCD HDTV

Hello everyone,

I'm having this weird issue the past couple weeks and it's driving me nuts. I hope someone here can help me.

I have a Samsung, 40 in. LCD HDTV 1080p. I have 2 HDMI ports - 1 hooked up to my Xbox 360 and 1 hooked up to my digital cable box. Recently I noticed that there are random "static" looking lines appearing at the top middle and bottom middle of the screen. However, they only really show up in "blacks" (or at least are only really visible then). I've seen them both on the Xbox and on the Cable tv. I've tried switching out the HDMI cables but the problem persists. The tv is about 6 years old and I never had this problem until the last couple weeks.

Any ideas? I could really use the help and really don't wanna have to buy a new tv.