Mobo, PSU burned out

[lbr]

though, you can try to perform a finger test : D
plug 1 7870, let it run for a while and measure temperature on the ATX power connector and motherboard power elements. If it is ok - add one more 7870 and so on..

[l3jmr]

Would it be ok if i replace 2*7870 with 2x7850? That would reduce power consupmtion for about 80W or so if my calculations are correct.

Thanks for help , i really appreciate it 

mm.
See, GPUs are using not only the power supplied by PCI-E power cables(http://www.hardcore-[Suspicious link removed]/images/psu/pcie6.jpeg) but also the power from PCI-e slot itself - http://en.wikipedia.org/wiki/PCI_Express#Pinout, see there are +12V power lines?

So what happened to your rig -
motherboard takes +12V from PSU using the ATX power plug(the one which burned)
motherboard then does something with that power(or not) using voltage regulator on the motherboard and gives it to GPUs on the PCI-e slot.
And your GPUs took too much power from PCI-e slots - so the weakest link burnt, usually the weakest link is the ATX power connector itself.

Now to anwser your question(replace 7870 with 7850) we need to know exactly how much power 7850/7870 are using from PCIe slot itself and for how much max power your ATX connector is rated and assuming that not only the connector burnt but also motherboard voltage regulator also - how much max power it can give.

That's a lot of questions ; )) That's why ppl usually use powered risers - consuming +12V directly from PSU and not using it from motherboard.

God damn that sounds complicated.

By finger test you mean touch the power connector and feel it if it's running too hot ? Sounds dangerous

[lbr]

imagine 5 alcoholics(GPU) drinking beer from a small beer keg(motherboard voltage regulator) connected with tiny in diameter straw(the stuff which burnt) to the huge beer canister(PSU)

so.. since alcoholics drink too fast, the tiny straw will burst cause of pressure; )))

now.. would not it be better to give each alcoholic a straw and plug each straw directly into huge canister(GPU+risers)?

[lbr]

yeah.. the easiest way to measure temperature is using your finger ; )))
unless you short something and you won't have some static on you and temperature is below 50c it will be okay

[ranlo]

Hi
you have to solder  wires from 12v line from  PSU to the pins in the normal riser (12v pins)

That's above my experties, i neither have the tools or the knowledge to do that

I only used power risers for 2 cards tho, since the board already got 3 slots that will fit the GPU. So can this still be the case ?

How can i make my own powered risers? I saw some on ebay but they cost 5 times as much as the normal ones.

Good question, and not something I know enough about. However...

Your PSU was 1050w. You were pulling nearly 1000w from the wall.

My understanding is that PSU's "deteriorate" over time (based on power calculators), something about capacitor age or something. Someone who knows more may be able to chime in but I think this could be related? Ex. the power being pushed by the PSU decreased over time until it could no longer handle the load and then was overloaded.

I have heared about the deteriorating PSU's over time aswell, however my PSU was only 2 months old - same with the motherboard so i'm not sure if that applys to my case aswell. I have had experience with broken down PSU's in the past but never like this. It usually is generating extreme heat and you can smell the plastic burning and then it explodes and doesnt work anymore. Mine still works however so i dont know

I'm going to go with what the others said then and say that it's power coming from the mobo that was the issue (need powered risers). My last PSU actually exploded (smelled burning, then 3 loud bangs and it quit working) but didn't fry anything, HOWEVER I was told that it was pretty lucky as it could have fried everything.

If the PSU is still running, though, the others are likely right.

[l3jmr]

Will try to get some cheap risers then i guess. One last question should i get 5 then for every GPU to have this additional power or just the ones i really need (pci-e 1x slots).

[ranlo]

Will try to get some cheap risers then i guess. One last question should i get 5 then for every GPU to have this additional power or just the ones i really need (pci-e 1x slots).

Most say you can get away with using them on like half, but I would say to go with them for all. Especially when dealing with hardware, I've learned that it's better to spend a little more now than risk losing a lot more in the future.