Corrosion? Or no?

[yusukeaoki]

Hi guys.
I was cleaning my MBP 17 today and came across these.
The white part were more brownish, some had the oily rainbow color, etc.
But the thing is Im not sure if these are like this or its a corrosion.

I dont recall spilling anything on my MBP throughout the middle of the body.
tried cleaning them with isopropyl alcohol with qtip but it didnt come off (Im guessing its not a corrosion then?)

Here are some of the pics. They seem to happen only around the screws.

Thanks in advance.

 

[BmwMPower05]

I have an early 2011 15inch and noticed almost the same thing in the first picture when I had to take out my SSD for a firmware upgrade. Just on the magsafe board, no where else. Ive seen this same thing on certain iMac components too, I wouldn't think too much about it. As for the other pictures, its normal, what looks like drops of glue. I think it might have something with protecting the components from the bottom plate.

 

[yusukeaoki]

I have an early 2011 15inch and noticed almost the same thing in the first picture when I had to take out my SSD for a firmware upgrade. Just on the magsafe board, no where else. Ive seen this same thing on certain iMac components too, I wouldn't think too much about it. As for the other pictures, its normal, what looks like drops of glue. I think it might have something with protecting the components from the bottom plate.

I see.
I dont recall seeing this before either because it wasnt there or I wasnt paying attention to it.
But glad to see others have similar thing thanks.

 

[BmwMPower05]

Im super OCD about my electronics. Especially my Apple products, I know water has never been spilt or even splashed on MBP before

 

[Brian Y]

It's normal . I believe the grounding areas around the screws are copper - hence why they oxidise .