[zicronix]

I have a Denon AVR-1800 reciver that got a weird himming noise when i connected my new HTPC



I have this...


Denon AVR-1800

Xbox, via composite video and optical audio

Playstation2, composite and optical audio

Cable box, composite and analog audio

Denon CD-player, analog audio

HTPC

Barco BG808s, VGA



All these are connected to the same outlet.


I hooked up the HTPC, power, keyb, mouse and LAN

but when i connected the Composite video from the reciver to my Pinnacle PCTV card the humming started...


If i disconnect the power from the HTPC it stops.


i can't understand why? is there a ground loop? what can be causing this?

 

[helzerr]

Certainly sounds like a ground loop problem to me... Disconnect one thing at a time until you isolate the problem. My money is on the cable box, the line coming in from the cable company probably isn't grounded properly and is causing your loop.

 

[HTPC Junky]

A simple solution for that is the grond loop isolator from Radio Shack. I added one between by cable box and stereo and it eliminated the hum completely. It works by eliminating a direct electrical path to the stereo. It couples the signal through a transformer.

http://www.radioshack.com/product.as...t%5Fid=270-054


Watch out to see if you need male-male adapters....it will help you avoid two trips to Radio Shack.

 

[zicronix]

I have a groubndloop isolator at home, i tried it but it didn't work with video...


i will try another thing first, i will disconnect the ground from the HTPC, as it worked yust fine when i had it in my bedroom and a longer cable. (i don't have a grounded outlet there).