: Its kinda Long: Sorry for asking for help here but many lvls in Marathon
: Eternal are quite hard.
No problem, this is where I expect people to come for help :-)
This level is actually much easier than it seems. You see, it was based off of a level from Marathon 2, and all the switches and such still (mostly) do what they did back then... which is not at all helpful or relevant to getting the chip to where it's supposed to go, because where it's supposed to go was not in the original level. It's kind of like "Come and Take Your Medicine" in Marathon 2: the level is big and sprawling and you could easily get lost if you went exploring, but once you figure out where you're supposed to be going, it's really quite easy to get there and get on with your mission.
One of the terminals somewhere tells you that you have to go "behind the curtains of fire" or something like that, and there is a picture of a deep cave with some lavefalls pouring down into the abyss. That cave with the lavafalls is very near to where you find the chip... VERY near. Though it looks like suicide, that's where you need to go. Just in dive head first and see where you come out. Your map will probably be useful here.