Corrosion on copper pci-e contact pins

[mfg_lv]

I've noticed corrosion on my pci-e sound card's pins:

It's weird because the graphics card has some damage around the same spot too. Also the RAM has some minor corrosion in two or three pins. Two questions:
1. What is causing this ?
2. How can I repair it if it gets to a point where one of the affected components is not working anymore ?

 

[Karsten75]

That looks more like electrical burn than corrosion.

 

[mfg_lv]

I cleaned it a bit and now the gold part on the two pins is gone, it's orange, so it means the copper underneath is almost intact.
Does anybody know what destroyed the gold coating ?

 

[Karsten75]

Bad electrical contacts will do that. Overcurrent will do that...

 

[mfg_lv]

I'm just trying to understand what is happening before it destroys my entire PC. You are not helping very much.

 

[Ragnarous]

I'm just trying to understand what is happening before it destroys my entire PC. You are not helping very much.

Since there is still no solution, I may bump this post and ask you, did it suffer any other damage? Shorting or such? Because it could be the PSU faulty or your motherboard! What are your updates?