Weird discoloration on motherboard.

[Mascleta]

So I was cleaning my pc today and while cleaning out the back I noticed these weird spots on the back of the motherboard. I think this might somehow be heat related but I don't really know. I doubt it's moisture because I wouldn't have a clue how it got there. I don't have any performance issues so I don't even know if it's a problem but I am curious to find out what it is.

[Windows7ge]

What motherboard do you have? It could be from the thermal pad that sometimes gets installed on a small metal backplate for the CPU VRM cooler.

[Mascleta]

B450 tomahawk max. What exactly would that pad do to cause this?

[eeeee1]

maybe something about the heat. what are your temps? (CPU and VRM)

[Windows7ge]

9 minutes ago, Mascleta said:

B450 tomahawk max. What exactly would that pad do to cause this?

The pads are slightly wet with a non-conductive liquid to help transfer the heat. They can leak or wick that liquid away. Based on what I can see it looks like it's coming from vias on the PCB. So the issue is the thermal pads on the other side of the motherboard.

 

This shouldn't be of concern. You can clean it with something like isophrophyl if you like but left as is this shouldn't hurt anything.

[-rascal-]

Looks like either remaining oils / flux from the assembly line at the factory.

Or (finger) oil or residue from when you were handling / putting the motherboard in.

 

In any case, using some rubbing / isopropyl alcohol should clean it off.

[Mascleta]

1 minute ago, Windows7ge said:

The pads are slightly wet with a non-conductive liquid to help transfer the heat. They can leak or wick that liquid away. Based on what I can see it looks like it's coming from vias on the PCB. So the issue is the thermal pads on the other side of the motherboard.

 

This shouldn't be of concern. You can clean it with something like isophrophyl if you like but left as is this shouldn't hurt anything.

Aaah okay, makes sense. Thanks a lot!

[Windows7ge]

37 minutes ago, Mascleta said:

Aaah okay, makes sense. Thanks a lot!

Down the road in a few years if you find the stains continuing to grow and your VRM temps start climbing you can look into changing the thermal pads under there. Should still last a long while though. You'll likely upgrade before it becomes a problem.