Water Damage ... Phone WORKS just no Sim reception

Hi guys,

My phone fell in the Pool a few days ago. Phone stayed on, turned on perfect after a few days. A few functions were inop, but came back after a bit of drying. Cameras, Power button etc.

Now, the only thing still NOT working is cell phone reception. Sim is fine, it just doesn’t receive a signal. It shows the Signal Bars so it knows a Sim is inserted.

I am very familiar with changing things myself on the Phone so I opened it up and inspected each part.

It was all dry but there were a few spots that had corrosion, see the pictures.

What’s the best way to clean them? Isopropyl alcohol? Metal brush?

Or is the antenna a specific part? Looks like it’s part of the motherboard….