What the hell is happening?

Hey guys

I took my 2 Gigabyte HD 7950's out of my case to remove dust etc, when I noticed on the back there was a discolouration/residue on the cards. Now naturally it has me worried, as these cards are out of warrenty and I was planning on selling them soon.

Both cards have been used for heavy gaming in crossfire and have stayed well with in their temprature limits (65-85 degrees celcius)

Anyone have an idea with whats happening or what it is?

http://imgur.com/35dJusQ

http://imgur.com/Xeg4A3T

Thanks.

Looks like something was overheating. If so, then I know it will reduce the life of the cards, but I don't know by how much.

If its sort of "bubbling" or sort of dry and "crisp" than it could just be the coating on the PCB coming off of the back. I have a Gigabyte 6850 that I am currently using and I noticed the same thing when I transferred cases a year ago. I have noticed no adverse effects thus far... 

 

Seems like the power delivery modules (mosfets, inductors) are overheating. Have you overclocked or increased the voltage on them?

Increased volts a small amount for about a month (1.3v), after that I ran the cards undervolted for the rest of their life span.

Stock is 1.25v and I found after my overclocking that even stock makes the cards run warmer than you would expect, so I undervolted to avoid that

 

 

What's the residue feel like? Me thinks that the solder mask is coming off around the VRM area

Yeah, the VRMs look like they're getting a bit toasty and affecting the PCB.

I'm currently at work, but I'll find out in a few hours time and post back.

Looks like flux to me.

That's what I thought at first as well but it is to spread out and there is not yellow coloration of the solder joints, also flux isn't used in reflow soldering and wave soldering

Since Both cards have the build up in the same areas, I initially was thinking that it may have been a condensation issue, where contact or close contact was being made with the fan housing or a plate.  So I went to look for some more visuals of the Gigabyte HD 7950, but found the following PDF instead.(it's old, but may apply)

http://www.kester.com/kester-content/uploads/2013/06/White_Residue.pdf

May also be a result from reactants left on the boards from their manufacturing process.  Again, I take the leap on that possibility because of the uniformity and similarity of the buildup on both cards.

(if those images are of the same card, then ignore this post completely please)

is it hummid where you live, looks like corrosion of some sort to me

Images are of separate cards, thanks for posting the link was an interesting read.

I'm in Australia, it gets relatively humid here. As of typing this it's 81%