There appears to be a "hiccup" on my home electrical system. Electrical devices have worked fine for years,

but Powerline adapters are upset by it.  I was using a Dlink, and then bought the TP-Link AV2000 thinking

that maybe the problem could be the powerline adapter. Unfortunately, it didn't make a difference.

I tried a different power outlet and different cables -- same thing.

So, the problem has to be in my home electrical system (new construction condo circa 2008). 

What happens is, every 20 minutes or so, like clockwork, the powerline connection drops for

a second or two, and then comes back, and then drops again, and then comes back.

Maybe 3 or 4 times and then it works consistently for another 20 minutes before it drops again.  

If I setup a computer to ping the connection, you see the ping go from 20ms to 500ms and

then no connection, and then it comes back. 

I'm on Google Fiber, btw. 

So, my questions are:

1. Is there is an easy way to triage my home electrical system?

2. Anyone have an idea what could be happening? (there is no appliance, like central A/C, that comes on with kind of regularity, btw). 

Thanks.