I'm not speaking of measuring the LNB voltage... That's usually a ONE
or a ZERO if ya know
what I mean. Critters & lawn mowers chewing on cables, etc. tend to do
that.

Np, on the link, I got more someplace if need be...

Remove the cover of the receiever.
Find the Power Supply Assembly. There is probably a metal shield
covering it, if Echostar.
Remove that too with the AC cord unplugged of course. Plug it back in.
There should be a
Molex style connector from the power supply feeding various assemblies
throughout the
receiver. Check the DC's for signs of AC ripple. Nominal DC's u'll see
are like +/-5V, +/-12V, so on.
If abnormal AC ripple is riding those rails, it can raise hell on the
receiver circuits (tuner assy, etc),
and can cause noisy reception like your seeing. It's something simple
you can verify in about 1/2
hour or less...If ya see questionable ripple just feel around very
carefully for signs of hot to the touch
Electrolytics (dried up), nothing there then ESR check the output
filter caps (closest to said molex
connector pins) I even have a schematic of the 90S power Supply if
that's what ur up against.
Not a very good copy, by any stretch, but worked for me. Without Rock
Solid DC's all bets are off.
P.S. - Was I right, Echostar Model SRD-5000???