MOBO fried, damage to other components?

sjandrewbsme

Senior member
Jan 1, 2007
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I just received my new board yesterday (Asus based 680i, not the striker). I was running various tests on it to check for stability.

I had the FSB with stock voltage @ 1550 and it was stable and running fine (running memtest86 and prime for an hour each). I tried 1600 with a slight bump in vcore (1.40v) and it wouldn't post - no big deal. But, I smelled a burning smell (uh oh). I noticed a small scorch mark behind one of the MOSFETs below the 1st PCIe slots. I have no idea how this happened as the vcore I was using (1.40v) is very timid (some people I've seen as high as 1.7) and it happened almost instantly. I think this was independant of the OC - but who knows.

At an FSB of 1550 I was at a core temp of 26 c (unloaded - Tuniq 120 air cooling outside the case in a rather cold office @ home).

I'm resigned to replacing the board. But - I am curious as to whether or not the CPU and RAM might also be damaged. The board will still not POST. The lights all work - the thing turns on and the fans work, but it will not produce any video output or POST beeps.

I don't have any other LGA775 boards to test the proc nor do I have any other boards to test the RAM. I'm 99% confident that there's nothing wrong with either - but I don't know.

I've confirmed the video card still works fine. I know the PSU works (and still works - in my other system).

The other thing - as soon as I received this board it looked like it was opened. There was no tape on anything and one anti-static checker bag was empty. And, the little cardboard frame piece in the packaging that has little pockets for holding the various accesories (cables, manual, audio card) was smashed and the accesories were just laying on top of it. Normally, it's neatly packed and the accesories are in their pockets (as they're designed to be). I'm wondering if something else might have happened here....

TIA for any input.
 

Operandi

Diamond Member
Oct 9, 1999
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There are MOSFETs by the PCI-E slots?

Anyway that is pretty a pretty strange occurrence. If the damage wasn't near the CPU then the CPU should be fine (I would think).

Also you can replace MOSFETs as long as you can find the right type if you have problems getting support from Asus or the retailer.
 

sjandrewbsme

Senior member
Jan 1, 2007
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I'm assuming it's a MOSFET - it's some sort of 3 pole transistor. It's about 1 cm below the top PCIe slot.

Here's a pic of the component I'm talking about:

http://home.comcast.net/~sjandrew.storage/board.jpg

It's barely perceptable - the scorch mark. I don't know for sure it's damaged. When it happend, it made a tell tale burning electrical smell. I thought my GPU was fried as it smelled like it was coming from there. It still worked in another board, so I know it's not the GPU. Then, I started looking closer and saw a slight haze on the varnish of the PCB right below that one component (I assume it's a MOSFET - looks just like one).

Even now you really really have to look closely to see anything out of the ordinary.
 

Operandi

Diamond Member
Oct 9, 1999
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Yeah, looks like a MOSFET alright.

It could have been defective and the mild OC pushed it over the edge, hard to say really.

There are real electrical experts over at Badcaps.net that may be able to give you a better idea of what went wrong.
 

SparkyJJO

Lifer
May 16, 2002
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You shouldn't have a problem RMA'ing the board, if it burned like that it was a defect of some sort. But you'll have to call asus, they don't respond to emails. The phone number is on their site under contact, you gotta dig a little bit to find it though.
 

sjandrewbsme

Senior member
Jan 1, 2007
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I'm sending it back to the vendor. I'm pretty sure I will get a replacement free of charge. In the meantime, I am just wondering if I have any worries about the RAM and processor. Would the fans spin up and attempt to POST with a bad CPU?

I'm not at all convinced that OC "broke" this. I think it exposed a flaw (as Sparky said). I'm pretty sure the board was not 100% new when I got it as it had some fingerprints on the back of the PCB and the packaging was in shambles.
 

Operandi

Diamond Member
Oct 9, 1999
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If the damaged MOSFET was near the PCI-E slot the damage should be isolated to that area.

And no you won't get any POST with a bad CPU or a non functional video card, in your case caused by the damaged PCI-E MOSFET.
 

zagood

Diamond Member
Mar 28, 2005
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Originally posted by: sjandrewbsme
I'm sending it back to the vendor. I'm pretty sure I will get a replacement free of charge. In the meantime, I am just wondering if I have any worries about the RAM and processor. Would the fans spin up and attempt to POST with a bad CPU?

I'm not at all convinced that OC "broke" this. I think it exposed a flaw (as Sparky said). I'm pretty sure the board was not 100% new when I got it as it had some fingerprints on the back of the PCB and the packaging was in shambles.

What vendor? I had a motherboard arrive like that from Directron, the IDE 2 went bad in about a week, too much of a hassle trying to get an RMA so just bought a PCI-IDE card that I still use to this day.

-z
 

sjandrewbsme

Senior member
Jan 1, 2007
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I already have the RMA and it's been approved (to send it back), it's from NewEgg.

I've sent a couple of things back to them without incident. They give me instant approval. I assume it goes back to them for some superficial inspection (if that) and they send back a replacement.

In reviewing the manual for the board and other things, I'm not sure what I did that's wrong with respect to the board. If the chip is fried, I think I'm SOL as I exceeded the maximum nameplate voltage. But, as far as the board is concerned - there are instructions and guides right in the manual to help for overclocking. There is also a special BIOS utility that's supposed to return the BIOS back to default if it hangs from too aggressive an overclock.

So, I don't know how I would react to a "Board failed due to overclocking" diagnosis - the board was designed to overclock. Also, I would be amazed if NewEgg (or any vendor for that matter) takes the board and runs it through a battery of tests to find out what's wrong. I think if they see it and there isn't obvious physical damage indicative of abuse or mis-use, they will send it back for a replacement.

From a cost standpoint, I don't think it makes economic sense to sit down and diagnose a problem like this - especially for a $200 board and a company that does billions in business every year.


 

Agentbolt

Diamond Member
Jul 9, 2004
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It's doubtful you damaged any components when this happened, however be aware fans will spin up with a bad CPU (you won't hear any POST attempts, though)
 

sjandrewbsme

Senior member
Jan 1, 2007
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Time will tell.

I don't think it's the CPU. The highest I saw the temp was like 29 celcius and the highest I got the vcore was 1.4

I wish I had another board to test.

The chip has no obvious damage - then again fried ones rarely do.