Do NOT lift grounds at this point! - John Swenson

Computer Audio Asylum

Music servers and other computer based digital audio technologies.

Do NOT lift grounds at this point!

Posted by John Swenson (A) on February 13, 2007 at 15:37:33

In Reply to: Re: Ground Loop with Mac Mini/Brick posted by terrapin on February 13, 2007 at 09:32:37:

If you are getting shocked when touching the volume knob you have something seriously wrong, do NOT use the system this way, its dangerous to your helth and could start a fire etc.

It really sounds like you have some significant leakage path from the AC line to chasis ground in one of your components and when you have the system grounded that current is getting shunted to ground through one of your interconnects which is where the hum comes from.

Some tests I would do:

Don't lift any grounds. Try system without mac n brick. Do you get hum? if not, connect brick to system, do NOT connect brick to mac. Do not plug in mac. Turn on system (including brick), do you get hum? If yes the brick is the problem. Turn it all off and don't turn the brick back on until you've talked to Gordon.

If no hum, do the test again with the mac connected and plugged in. Does that hum? If yes its the mac's fault, get it serviced.

Do these tests for the shortest possible time and don't lift any grounds. This could be a serious health and safety issue.

John S.

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Follow Ups Full Thread

Topic - Ground Loop with Mac Mini/Brick - terrapin 07:23:52 02/13/07 (15)

Well some ideas.. - Gordon Rankin 13:08:27 02/14/07 (1)

Thanks for all the help. - terrapin 17:05:15 02/14/07 (0)

a battery power pack.. - juanitox 05:27:53 02/14/07 (1)

Why batteries don't work with the Brick - Gordon Rankin 13:14:11 02/14/07 (0)

Re: Ground Loop with Mac Mini/Brick - BrassTeacher 22:21:10 02/13/07 (0)

I had a similar problem in adding a PC which had a - Flatmap 12:11:15 02/13/07 (2)

Re: I had a similar problem in adding a PC which had a - terrapin 12:16:50 02/13/07 (1)

Yikes! - Flatmap 20:45:57 02/13/07 (0)

Re: Ground Loop with Mac Mini/Brick - audioengr 09:58:08 02/13/07 (2)

Re: Ground Loop with Mac Mini/Brick - terrapin 10:06:04 02/13/07 (1)

Re: Ground Loop with Mac Mini/Brick - audioengr 16:39:59 02/13/07 (0)

Re: Ground Loop with Mac Mini/Brick - bshapiro 09:11:30 02/13/07 (3)

Re: Ground Loop with Mac Mini/Brick - terrapin 09:32:37 02/13/07 (2)

Do NOT lift grounds at this point! - John Swenson 15:37:33 02/13/07 (0)

Re: Ground Loop with Mac Mini/Brick - bshapiro 09:53:35 02/13/07 (0)

Follow Ups

Do NOT lift grounds at this point! - John Swenson 15:37:33 02/13/07 (0)

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