Probe point corrosion -Macbook repair

[Askic]

Hello guys,

I'm learning about logic board (motherboards) repairs. I don't do repairs professionally, but I manage from time to time to repair something for my family and friends.

What caught my attention is this visual inspection guide written by Louis Rossmann. It seems that corosion on probe points on the motherboard can "kill" Macbook. https://wiki2.rossmanngroup.com/inde...ual_inspection
I wonder how corrosion cause this. If there is a track that has a probe point made on it and corrosion is build up on that place, does this means that corrosion effectively break the track here?
Is this accurate conclusion?

I notice that only macbooks have this many probe points comparing to other manufacturers.

[zpi]

Re: Probe point corrosion -Macbook repair

Hello,

You are correct. A lot of probe points are not critical if they corode away. But others are imortant.

1v------------o-------CPU : if this corodes away, you are not having continuity to CPU

.....CPU
...... |
.......|
...... |
1v---Y---------o : In this case, you still have continuity to CPU


Dont know if my keyboard drawing is understandable

---- is track
o is test point.

[Askic]

Re: Probe point corrosion -Macbook repair

Hello,

You are correct. A lot of probe points are not critical if they corode away. But others are imortant.

1v------------o-------CPU : if this corodes away, you are not having continuity to CPU

.....CPU
...... |
.......|
...... |
1v---Y---------o : In this case, you still have continuity to CPU


Dont know if my keyboard drawing is understandable

---- is track
o is test point.

Perfectly understandable. One would expect that all probe test points are made like shown in the second drawing. I think the first drawing (which is obviously implemented in many cases) can be considered a design flaw.

[zpi]

Re: Probe point corrosion -Macbook repair

Probably it is made in this way because of trying to design smaller boards. If boards would be designed to last and our society would be not so consuming, then boards would look much different. Also in these days to make liquid resistant boards are very easy, but they are not . So lets fix some boards till they are shitty

[Askic]

Re: Probe point corrosion -Macbook repair

I understand that, but would it be a problem to put a small drop of solder on each test pin? This way area below solder would be protected and the track could never be broken by corrosion. Really strange design to me.