update:
chromeos15-row13a-rack5-host7 (nami) also need to be reconnected

https://stainless.corp.google.com/search?view=matrix&row=model&col=build&first_date=2018-11-06&last_date=2018-11-12&test=audio_AudioBasicExternalMicrophone&hostname=chromeos15-row13a-rack5-host7&status=GOOD&status=WARN&status=FAIL&status=ERROR&status=ABORT&exclude_cts=true&exclude_not_run=false&exclude_non_release=true&exclude_au=true&exclude_acts=true&exclude_retried=true&exclude_non_production=false

Thanks for filing the bug yuhsuan@.

Matt, please check what boards and their respective hosts need attention from lan team.

https://stainless.corp.google.com/search?view=matrix&row=build&col=board&days=7&test=audio_AudioBasicExternalMicrophone&status=GOOD&status=WARN&status=FAIL&status=ERROR&status=ABORT&exclude_cts=true&exclude_not_run=false&exclude_non_release=true&exclude_au=true&exclude_acts=true&exclude_retried=true&exclude_non_production=false

I guess the move from row 13 to row 14 might have caused some flakiness.

filed b/119407559

Nami devices mentioned in c#1 have an issue with the audio node names: https://bugs.chromium.org/p/chromium/issues/detail?id=901723

I think problem on Nami is not related to audio node name issue. It should be MIC when audio jack connected. I think it's just a problem about connection between chameleon and DUT. Actually, you can see the test still fails after that issue fixed.

I found the another problem on Nami and filed issue at  crbug.com/907996 .
I think it's why Nami keep failing these test.
We need to check whether the DUT can detect audio jack when we plugging it.

b/119407559 is resolved. Marking this fixed.