I have a loud hum when I connect my new Sony LCD HDTV to my HD cable box. Here's my configuration:
Coax from wall to HD cable box Cable In coax
RCA cables red/green/blue out from cable box to Component 1 red/green/blue inputs on TV
RCA Audio red/white out HD cable box from to Component 1 Audio In red/white on TV
This is when the hum starts. If I unplug the RCA red/white cables from the TV, the hum stops. But of course, then there is no TV sound. If I use coax cable instead of RCA cables, the hum stops, but the video is very poor.

Know a fix?

Ground Loop Isolator?
http://www.avsupplystore.com/jen-vrd1ff.html

Any difference between these (besides price)?
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=265-012

I believe there is a DVI out on the back of the cable box. Could I use a DVI/HDMI cable from the box to the second HDMI jack on the TV? Would this replace all 5 RCA cables? Better, worse, not possible, etc.

Suggestions?