[SOLVED] What are those white stains on the back of this GPU?

[pippirippi]

I've got this used GPU which has some white stains on its back. What are those? I've searched the web and from what I understand they could be flux residues but I'm not sure. Any other idea? Looks like this GPU was removed from a working PC and it was still functioning when it was removed. Then it sat in its own box for maybe a couple of years and now it was given to me. I've not tested it yet and I'm not sure if it's safe to power it on before removing that white stuff. Anybody knows what that is? Is it harmful? Should I worry? Can I leave it there or should I clean it even if the GPU works? I don't know when those white marks appeared, if the card was sold like that or if they appeared later during daily usage.
Thank you all for any help.

 

[Schlachtwolf]

The make and model would be useful to know....

 

[pippirippi]

sapphire hd7870

 

[Schlachtwolf]

It looks like residue from cleaning more than corrosion so gently cleaning with some isopropyl alcohol should remove it, use a coffe filter but not a tissue as that can leave fibers in the board. If it is only a leftover residue it should not impact the performance of the card.

Is it working as expected? Being an older GPU corrosion is possible if it was in a humid enviorment for a time but as it is a used card it is a case of you pay your money and take your chance.

Make sure though it is DRY after cleaning before you power it up !!!

Hope it works out for you

Cheers

 

[pippirippi]

Thank you for your help.
I've not tried it yet so I don't know if it powers up at all. I was unsure if I should try to clean it before testing.