Terry wrote:

snip

they say it is the cable and not the box and they
want to make the 75$ service call.

If they say it is 'the cable' and assuming it is not their input
cable, then why not simply buzz down to Radio Shack or Circuit City
and get another cable to determine if that is the problem? It
shouldn't cost much and it might just work. Minor corrosion can make
high frequency stuff go funky. Happens more often in field prepared
cabling than factory built assemblies/
If the experiment fails, then switching companies seems logical. Good
luck.

Joe