Direct TV and digital hum problems

I hooked up a digital 5.1 reciever for a non audio bud tonight I donated to him. When I hooked up his Sat box via Roslink I got a high pitch faint but annoying hum thry speakers. I figured I would try dig coax and same result. I lastly hooked it up for Pro logic and no hum but its not digital as I had hoped to give him.
I lifted the ground, checked the ground at the junction amp in basement and all settings were verified.
I am by no means new at this, I have over $50k in my home theater and have done surround for over 15yrs all along being a DIY installer (I am also the nerd everyone calls for help.........and am pretty good at it too :)
My point is that I have tons of experience and just cant figure this out, hope some ideas come my way..........thanks all!
ground loop thru cable co-ax? Try ground isolation transformer on the co-ax. A good trial is to put two of those 300 ohm to 75 x-formers back to back. co-ax to 75 ohm to 300 ohm to 300 ohm to 75 ohm to co-ax.
I got a high pitch faint but annoying hum thry speakers.

I don't think the problem is a earthed ground loop problem.A 60 hertz ground loop hum is not high pitched. It is a 60Hz low level hum.

Is it possible you are getting a feedback loop somehow?
Is this the only digital input being used on his pre/pro.
If it is try a digital connect to his CDP, it may be his Pre/Pro. One other thought is phone line, did you hook up the phone line as DTV so loves us to do. Disconnect it and see what happens, but my first thought is the Pre/pro is generating a hum withing the digital to analog circuitry.
Not an expert here just have had DTC for about 12 yrs and this is a thought of something to try.