Please help, my new build likes to catch on fire...

jstwinkles

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Jul 12, 2009
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Okay, so I recently put together my very first gaming rig. I'll list the specs at the end of the post. Anyway, the PSU that I originally bought was inadequate, and as a result, it died. It was working great, but then died while I was using it. I'm assuming it died after a spike in the amount of power needed, which would explain why it was working until then. So I bought the PSU that is listed down in the specs. Well, I installed it no problem, but as soon as I hit the power switch I hear this loud hissing and sparking sound. I then smelled burnt computer innards. I look down to see a small flame at what appears to be one of the SATA connections on the MB. Needless to say, I shut it off immediately, but when I opened her up later, there was no apparent damage. Something I did notice however, was the fact that the SATA cable that I was using at that particular plug had a metal clip to hold it in place. I simply assumed the metal on the clip had shorted something out. So I replaced it with a cable that doesn't have a metal clip and after hooking everything back up I hit the power switch and was pleasantly surprised to see that everything still worked as it should.

I have been using it for 3-4 days since this with no problem whatsoever, until tonight. While I was in the middle of playing a rousing game of Fallout 3, it just shuts down completely with no warning. I waited a few seconds and then hit the power switch, only to hear the same hissing and sparking sound as before, along with the wonderful smell of burnt computer, but no flame. I unplugged everything as before and checked the inside once again. No visible damage. I do understand that even though I can't see any damage, there still could be some, but just to see if it would magically come back to life, I plugged in the power cord and hit the switch. It came on with no problems and went through POST successfully. Needless to say, I am completely stumped. Does anyone know why my rig seems to want to try and catch fire randomly, and why it then decides to work after a few minutes? Oh, and sorry for the lengthy post, I just wanted to make sure I included every little detail that might mean something.

Here are the specs:
MB: ZOTAC NF780I-A-E LGA 775 NVIDIA nForce 780i SLI ATX Intel Motherboard
CPU: Intel Core 2 Quad Q9550 Yorkfield 2.83GHz 12MB L2 Cache LGA 775 95W Quad-Core Processor
PSU: CORSAIR CMPSU-750TX 750W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply
RAM: 4 sticks of Crucial 2GB 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Desktop Memory Model CT25664AA800
Graphics Card: VisionTek 900244 Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card
 

tecmo34

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My suggestion would be remove the MOBO and make sure it isn't touching/being touched by the motherboard tray... The MOBO standoff's are doing their job.

I'm a little worried for you that you have already done enough damage to your MOBO that a RMA might be required.

Just double check your MOBO isn't being touched by a metal object and go from there...
 

jstwinkles

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Jul 12, 2009
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thanks for the advice. I'll check that out as soon as I get the chance, but let's just say that for the sake of argument, there isn't a problem with grounding. What then?
 
The same SATA mobo connector shorted out twice using two different cables? If there's no assembly-related short of/on the mobo (which you can ensure by assembling outside the case) . . . well, what's at the other end of that cable lol?

One end or the other is pulling too much current.
 
Build the thing outside the case. It's called breadboarding. It will end up looking something like this:
http://www.tomshardware.co.uk/forum/page-262730_13_0.html
You can turn on the PC by shorting the two pins that the case power switch goes on.

Run it for a while. If you do not see any sign of arcs 'n sparks, it means that you probably had some kind of assembly problem. If you do see arcs and sparks, that means the case was not the problem. Either way, you learn something.
 

jstwinkles

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Jul 12, 2009
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thanks everyone for your help. unfortunately, my rma period of 30 days just expired on the mobo so i'm out of luck there. Anyway, I think I'll try the breadboard idea (thanks for the tip jsc and twoboxer!) The only thing that worries me is that the sparking seems to be occurring at random intervals. If I could figure out what to do to induce it I'm sure I could figure out what is causing the problem. So I'm afraid that when I do the breadboard test it'll run just fine but then weeks later decide to catch on fire again. Oh well.
 

rkaye

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Mar 28, 2009
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too much thermal paste maybe? that goof conducts electricity, and if it seeps out from between the cpu and cooler and drips onto the motherboard, nothing good will come of it.. run a q-tip around the edge of the cpu ,...

 

jstwinkles

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Jul 12, 2009
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nope, I checked all around it and no spillage. Besides, the thermal paste was the stuff that came pre-applied to the stock fan.

And I'll keep that last little tidbit in mind. ;)
 

rkaye

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Mar 28, 2009
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hmm. bummer. was hoping it'd be an easy one. on the motherboard, are any of the capacitors ('upside-down thimble' looking things) look like they are split or leaking? somehow i can't see the psu causing the problem. :(
 

jstwinkles

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Jul 12, 2009
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ha! Finally found the culprit. As I was taking it apart to do the breadboarding I found a place on the graphics card that was burnt to a blackened crisp. Apparently it was on a part of the card that wasn't visible until I took it out of the slot and inspected it. As to the SATA connections catching on fire, I think in my haste I mistook the flame on the graphics card for being on the SATA connection because they are both red and right next to each other. Who knows why it decided to fry in the first place. I'm assuming it was the original PSU that did it when it got fried. Oh well. I've contacted Visiontek; hopefully they'll give me an rma. Fingers crossed. Thanks everybody!