Standard horizon gx2200- noise on power down and ram mic not work.

[Therapi]

I just installed a new gx2200. Everything seems to work well, except it will not work with our RAM3 mic. Well, the ram can power it up, but there is no other functionality with the ram. No data on the ram screen either.

When I power down the radio, it continues to make a popping noise for quite a while. It will stop if I flip the switch for its circuit.

Of course, I will contact standard horizon about this when they open next week, but what do you think the issue could be?