Quote from: coda on November 24, 2013, 11:07:30 AM

hello

Something very strange happened to my 6 month old Corsair AX 860 PSU
I'm mining steady since months with no problem @ 1830kH/735W av

I've got 3 undervolted + a little overclocked sapphire 7950
with one mobo Asrock970 extreme4 + normal PPCIe risers

But one morning i woke up and the rig was unpowered !

I tried to restart several times but the miner doesn't want to
Sometimes it switch on, worked maybe 1 sec and then off ...
But all the rest seems working

When i disconnected the power cable from the ATX 24 PIN cable from the PSU
it was like "glued" ... i finally managed to unplug it

I don't understand what happened ...

After some investigations, i've noticed that this kind of problem may come when
too much power is taken from the mother board PCIe ports, but normally mine
can handle 3 x 7950 with no problem ...

example of a typical burned mobo

I noticed everytimes this happens, this is on the mobo side ...
Not on the PSU side connectors like me, does it means something ?

3 days before i had 1s instant down/restart of the whole house mains because of the bad weather
fortunately nothing in my equipments was damaged and the miner restarted without any problem
I think house mains power problems would damage differently the equipment, and i have a APC power surge protector on the miner...

Maybe, the only mistake i made is to forget a common ground for GPUs, PSU an mobo as i got a plastic/wood open case...

Maybe some "conductive" dust like metal (f*ck knows why it's here) created some dangerous connections between electronic parts and have made something ... but i haven't noticed anything like this
and but i don't really trust it ...

Or maybe it is a issue due to software, because it can ask the graphic cards to work more than expected
(cgminer, trixx, drivers ?)

One day before, i've just maid a fresh reinstall of SKD and catalyst cause i lost a litttle from my "normal" perfomances ( it worked - normal performances were back ) after a break of one month mining.
And also i tested some new versions of cg miner but i decided to not use them because of no change of perfs or not working at all ... (last version for ex asked me "waiting for a usb hotpug" ??)

So i re ordered a PSU + some powered risers, and do a common grounding, but the mystery is still here ... do you have any ideas of what happens ?

thanks

I've burned a few PSU's mining, but hey. I broke even. Tongue