For my Q16, it's not corrosion, but overheating.
Reading again the full topic, I'm wandering if the culprit was not the Com card, but me (I don't remember exactly, it was a very long time ago) using a grey power supply in place of the white one.
Hi
I found your topic searching for "Macintosh portable Q16". I've opened my Portable for the first time yesterday, because I wanted to recap it after some years in my attic. One of the last time I used it, many years ago, I have tried to install the Com card, and instantly I've got a burn...