Blackened power connectors

[not.you]

I posted about this some months back in the S9 thread but didn't get much in the way of comments.  I am wondering when I should be concerned about this and what, if anything, I can do about it.  It has definitely gotten progressively worse.  This is one of the autotune S9's (13.5 Th) and it is only happening on two of the boards, so clearly the two drawing the most power (it tunes to 653, 653, 572 freq on the three boards).  Since it is an autotune miner there is no way to downclock it or I would.  I am using an EVGA 1600.  The connectors are definitely hot to the touch.  Weather they are hotter now than they used to be I can't say.  The miner has been running for like 9 months or so.  I'm kind of to the point that I don't want to just wait for the fire and would like to find a solution before that happens.

[VRobb]

I'd power down, disconnect the PCIe plugs to the hashboards, clean the contacts and plugs, and then apply a little conductive contact grease.  Power back up and check temps after it's run for a while.  Should help a lot, always does for me!

-And to add to Hagss, you're looking for any conductive contact grease, NOT dielectric.  They're opposites!

[HagssFIN]

Yeah there is definitely something wrong with the contact.

I second VRobb's advice.

I don't know what is available in the US, but as I work here in Finland as an electrician I use this contact grease http://products.ensto.com/catalog/specification/13174/specification_SR1_ENG1.pdf

[Elphamyto]

This happens semi-frequently to me over time. Usually I notice it around the time I need to upgrade machines (e.g. A6 to A7's or S7 to S9's). I think what is happening is that the PCI connector pins are getting strained over time in certain areas (especially where you have 6+2 pin PCIE connectors which ATX PSU's provide) and high resistance starts manifesting around the pin matings, which in turn blackens/melts the nylon connectors. The white color is easier to spot; the black PCI connectors from the PSU side are usually in much worse condition. I have found that the situation progresses once it starts and quickly melts both male and female connectors (you can usually smell the melting nylon as this happens). In some cases I've removed the hash boards, desoldered and removed the old PCI connectors, and soldered new ones on.

[not.you]

How would I go about cleaning the connectors prior to applying the grease?

Where do I apply the grease?  To the plug portion on the miner?  Or will there be instructions that make sense when I buy it?


Does this look about right?
https://www.google.com/shopping/product/7792073942260243973?q=conductive+grease&biw=1680&bih=894&sa=X&ved=0ahUKEwiB-7ay253WAhVLs1QKHfb1A00Q8wII_AIwBQ

Or this?
http://www.voltlighting.com/outdoor-landscape-lighting-grease/p/VAC-GREASE1?gclid=EAIaIQobChMI3Ombvdyd1gIVSFgNCh2jHQdVEAkYBSABEgLTefD_BwE

This?
https://www.grainger.com/product/35RV29

[VRobb]

I'd go with the first one for the grease, but that's just me since both would do the job, and as for cleaning you just do as best you can, though if you want to get into it you could also get contact cleaner to start.  Get some Q-tips or small foam/sponge pieces and buff the metal clean.  If you have a mircro screwdriver set you can wrap a small one with a layer of tissue for the socket side.  Apply the grease - which side doesn't matter really since once you slide the connector on it'll get schmeared around.  Don't put on too much, and I usually do 2 or 3 connect/disconnect to get the grease all over the contacts.
Then you should be good to go!

[not.you]

I'd go with the first one for the grease, but that's just me since both would do the job, and as for cleaning you just do as best you can, though if you want to get into it you could also get contact cleaner to start.  Get some Q-tips or small foam/sponge pieces and buff the metal clean.  If you have a mircro screwdriver set you can wrap a small one with a layer of tissue for the socket side.  Apply the grease - which side doesn't matter really since once you slide the connector on it'll get schmeared around.  Don't put on too much, and I usually do 2 or 3 connect/disconnect to get the grease all over the contacts.
Then you should be good to go!

Thanks for all the responses.  You guys rock.  

What do you think about the third product I listed above (I edited the post)?  That one looks like the handy little syringe looking thing may make application easier.

EDIT: Just to follow up on this, I bought the third one with the injector.  It works great!  The syringe thing made application super easy, just inject it into the holes in the male connector of the PSU cable.  I am surprised by how much difference this makes in the temp of the cables and connectors.  I had no idea this stuff existed.  So thanks again for the responses.