Hum problem


System hum when cable box is connected. How to get rid of it?
ellyjr
Checked cable junction box outside the house, I opened the box and found that they forgot to hook up the ground wire. I hooked up the wire, no more HUM!!!!! Great advice Bob. Thank you everyone for all your help.
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Be aware that isolation devices can introduce little gremlins that will mess with some channels if you have digital cable. I had a Time-Warner tech come out when I first moved in because I wasn't getting several channels that I should have been - he isolated the problem as the Mondial Magic I had in line between the cable outlet and my cable box (which is connected to my DAC via toslink).

I felt pretty stupid, but then again, was totally unaware that those isolation boxes can cause such problems with the newer digital TV boxes (was a non-issue with the older, non-digital boxes I'd had in the past).
It is the cable tv line that cause the hum not cable box. Will the isolator fix this? thanks again.

If you disconnect the incoming CATV coax cable from the TV and the hum stops, then yes the isolator will stop the ground loop hum.
Thank you. I disconnected the cable box, unplug it from the wall, now I connected the cable straight to TV, the hum is still there (the only wire that link to the system is the hdmi cable from Bluray player to TV). It is the cable tv line that cause the hum not cable box. Will the isolator fix this? thanks again
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