Your receiver wouldn't be an Echostar SRD-5000 by any chance would
it???

If so, they are prone to having bad Caps in the Power Supply Assembly,
commonly called a Model 90S Power Supply. The symptom is usually
a little more catastrophic, but could just as easily be causing your
problem.
I've got one of those laying around collecting dust that has a bad
Microprocessor board...
but the power supply was confirmed OK in another unit. In any event,
I'm pretty sure they
used that same design power supply in other Echostar models as well.

Easiest way to check is look for signs of AC Ripple with a DMM on ALL
of the DC voltage Sources
leaving the Power Supply. I have taken that module out of the chassis
before, and simply
replaced every Cap on the output side of the switcher, as when one goes
bad, the rest are well on their
way as well. Analog C-Band Satellite Receivers generate a lot of heat,
and normally don't vent very well
buried in people's TV cabinets & such, so it's very common for the
Filter Caps to dry up inside over the years.
The sudden nature of your problem (e.g. worked until 6 mos ago) leads
me to believe that might be what ur up
against now that I think of it

So

A.) Read that link
B.) Swap Receivers if possible.
C.) Check your cables.
D.) Check your Power Supply.

Bill