Mark, You can try using a three prong to two prong adapter (the kind used to plug a grounded plug into an ungrounded socket--for this experiment do not connect or allow the metal tab of the adapter to touch the screw of the outlet)on any connected device to drop the ground. If this works you...
As a newbie to this forum let me thank all of you for your interesting and informative posts. If anyone here also belongs to the TiVo forum you may know me as Jlwine. I too have an Anthem AVM 20. I originally demoed than purchased one back in 2001. Interestingly enough my original demo machine...