24pin ATX melted with after installing SLI

[xivlia]

hi there, i have recently bought another GTX 480. and i added it to my rig yesterday, it was working perfectly fine untill today. my pc randomly shut off while playing Dragon Age: Origins. and it would not come on when i pressed the power button. so i left it there for about 15mins. and tried again and it powered on, but it wouldnt POST. all it would do is. power on for 3 seconds and power off for 3 second and then power on for 3 seconds and so on. and it would do this forever untill i turned off the PSU at the back. i have a be quiet dark power pro 1000W and thought the gtx 480 sli was darwing too much power. so i discconected everything and took the 20+4pin ATX cable out and on the 4pin part. one of the pins has litterally melted. so im guessing the motherboard is also screwed. however. when i take off one of the gtx 480 and connect the ATX cable it works even though one of the pins have melted. it still shutts off randomly from time to time though. and i have checked both of my 480's one by one and they are also working fine. but when it comes to SLI it just wont post... another thing is that everytime i take a component out and put back in, my BIOS settings get reset for some odd reason. so is my PSU not working or is my Motherboard not working?

oh and my CPU was NOT OC'ed at the time

here are some pictures. off the damage

[watercooled]

Strange how it's only the one pin as there are a number of other 12v pins which should all be tied together. Maybe the other pins aren't soldered on to the motherboard correctly? What motherboard are you using? Also what brand of graphics card?

[Sputnik]

The pin that is burned should have a yellow wire going to it ( I can't see clearly in the photo).

I guess one of your PCIe connectors might not be providing enough (or any) power and the graphics card is trying to pull excess current through the motherboard?

[jim]

Your PSU is definitely up to the job in terms of spec... something has gone badly wrong with one of the components

[xivlia]

Could it be a loose connection ? I've cleaned the burnt out connection on the motherboard and stripped the melted plug (so the metal connector is exposed). Now it fits better and the pc has been on overnight with no problems, yet.

Also, there is a hissing sounds. I think its coming from the psu but can't tell exaclty. Could this a capacitor leak ? Is this a major problem ?

Thanks.

[Biscuit]

Is this a major problem ?

I would say so...

When something melts and starts making strange noises its usually time to get in touch with the supplier to get a warranty replacement. Its a good thing your other components are ok but i wouldn't risk using that PSU a moment longer incase it causes any permanent damage

[planet436]

It could be arcing http://en.wikipedia.org/wiki/Electric_arc, caused by a loose connection. If you've burned part of the motherboard I would definitely RMA it. The PSU may be okay but I wouldn't risk it so RMA that as well.

The CPU sounds irrelevant in this case, so if it wasn't a loose connection it will be the draw the 480s are putting on the PSU. That PSU should be able to handle the draw but might have been unlucky. Were the 480s overvolved?

[xivlia]

I would say so...

When something melts and starts making strange noises its usually time to get in touch with the supplier to get a warranty replacement. Its a good thing your other components are ok but i wouldn't risk using that PSU a moment longer incase it causes any permanent damage

Well I'm using the pc right now...I probably should get a new psu since when I turned it on from the back yesterday (before switching on the pc), there was a small pop, with a flame :S and it smelled like burning a bit too....this happened after the melted pins. Sounds really bad but its still working.

[xivlia]

It could be arcing, caused by a loose connection. If you've burned part of the motherboard I would definitely RMA it. The PSU may be okay but I wouldn't risk it so RMA that as well.

The CPU sounds irrelevant in this case, so if it wasn't a loose connection it will be the draw the 480s are putting on the PSU. That PSU should be able to handle the draw but might have been unlucky. Were the 480s overvolved?

I don't think I can RMA any of these components, as I've bought them over 3 years ago.

Nothing was overclocked or overvolted when this happened.

[planet436]

Well I'm using the pc right now...I probably should get a new psu since when I turned it on from the back yesterday (before switching on the pc), there was a small pop, with a flame :S and it smelled like burning a bit too....this happened after the melted pins. Sounds really bad but its still working.

If that's not a sign to get a new PSU I don't know what is

[Biscuit]

I suspect planet is correct and it is arcing which has caused the problem. As i said before, if it was me i would stop using it completely and replace the power supply regardless of if it seems ok now.

[watercooled]

Arcing requires a voltage differential between the contacts - in a functional system there should be 0v (or more realistically, a negligible voltage) between a 12v pin and socket since they are (or should be) tied together at both the PSU and the motherboard. Even without arcing this could have just happened if all the 12v current was going through that single pin, the extra GPU would have added extra load to it heating it up further. Current will take the path of least resistance. I suspect there may be un-soldered pins as I said originally - do you have a multimeter you could do a continuity test with?

[xivlia]

Arcing requires a voltage differential between the contacts - in a functional system there should be 0v (or more realistically, a negligible voltage) between a 12v pin and socket since they are (or should be) tied together at both the PSU and the motherboard. Even without arcing this could have just happened if all the 12v current was going through that single pin, the extra GPU would have added extra load to it heating it up further. Current will take the path of least resistance. I suspect there may be un-soldered pins as I said originally - do you have a multimeter you could do a continuity test with?

No, I don't have a multimeter. What could cause all of the 12v current to flow through a single pin ?

[Tattysnuc]

.... a break in the supply of current elsewhere that the component is trying to draw.
If you had a "dry connection" or simply no connection at all on the other yellow-connected pin, that might do it.

Feel the wire connected to the one that arced - is it getting warm? If so that's a sure fire sign that the problems ongoing. The pop you heard was possibly a capacitor blowing in the PSU.

Sounds to me like the PSU either was at fault, or is now at fault... I'd really advise that you power down and leave off until you've replaced.

[watercooled]

Yep, a cap blowing won't necessarily immediately kill the power supply - it's likely a filter cap so ripple may have increased. High ripple isn't something easily noticeable but it puts extra stress on components in your computer, depending on the magnitude it might start to take out stuff like VRM circuits which in turn can inflict damage on the more expensive bits. In short, I wouldn't still be using that PSU.

[Pob255]

What PSU was this? make and model?
esp as you where trying to run 2x gtx480 which are one of the most power hungry cards.

Could of been a dodgy connection.

looks like the motherboard was pulling gpu current through that one pin, which is odd.
hard to say much more without knowing what your other components are.