Solved I need help - a possible electrical short

Gigabyte motherboard / Ga-h97-d3h
April 6, 2015 at 07:45:28
Specs: Windows 7 64 bit Ultimate, i7 4790 \ 24 Gb's GSKILL 1600 DDR3
I'm trying to diagnose a problem that appears to me to be some kind of electrical short, but I'm not sure.

Here's what happened:

I was rendering a vid in the background, and watching a youtube vid when my computer just shut off. No strange sound, no warning, it just went dead.

But I need to backup. A couple days ago I just put my build into a new case - the Fractal Design R4. Today I was trying different drive configurations to get the best cooling. I had moved the drives around to different bays until I found a sweet spot. My drives dropped from near 40C to between 27 to 30C - which seemed like a lot to me, but hey I figured everything was good. Now I'm thinking the excess heat originally may have been due to an electrical problem, because this figures in later.

After the computer died I just tried switching the PSU off and back on from the back and pressing the computers power button. Nothing. The PSU is a SeaSonic S12II 620W Bronze. I tried the obvious stuff ... unplugged from the surge protector, tried a wall outlet, different psu power cable - all did nothing. My USB backups and monitors were working off the surge protector so I knew it was good.

Then I removed the PSU and tried the jumper trick on the 24 pin connector. It came on.

When I put the PSU back in, and reconnected everything, the computer wouldn't turn on again .... at least not the first time. About the 5th or 6th time trying it from the case power switch it came on briefly and then went off. I disconnected everything except the 24 and 8 pin power and it came on and stayed on. Thinking this might be a problem with either the 3 or 5 volt rail I decided to try another PSU- a Cooler Master GX 450 W Bronze that I absolutely know was working form another build. The Cooler Master has only about 3 months use on it. I plugged it in with just the 6, 8 and 24 pin power and tried it and the computer came on by pressing the case's power switch. But when I hooked up the drives, the monitors, USB peripherals etc, it wouldn't turn on.

I disconnected the monitors, and peripherals and tested it on my bench. It wouldn't come on. I disconnected everything except the 6, 8 and 24 pin power and it came on. Same as with the Seagate PSU. This time I started to reconnect things one by one. Eventually through the process of elimination I discovered that If I plugged in one of my HDD's - a 3 TB WD black - it prevented the computer from coming on. Just to check this theory again, I reconnected the 3 TB drive and turned the power on. It powered on, but there was an instantaneous puff of smoke from the 3 TB drive (goodbye 3 TB WD Black drive), that horrible eclectical smell, and the computer shut down. And I immediately pulled the plug.

So leaving that drive disconnected and the Cooler Master GX 450 PSU connected I tried it again. It powered on as normal with my three other drives connected. I reconnected everything - two monitors, 3 USB drives, and all temps good and running now about an hour. But I'm worried this is a larger problem.

I've never heard of an HDD causing an electrical problem, shutting a system down and then preventing it from starting. I guess if the wiring is bad, but...? So I'm thinking it's possible there's a short somewhere, and that something else might be next.

Possibilities ...

When I mounted my mobo in the Design R4 case, the mobo had one odd stand off hole, with no corresponding hole in the case. I measured and drilled one and it lined up perfectly and I was able to thread the stand off in tightly. The bit I used was smaller so it took some effort to thread it in,. so it's tight. But is it possible that this could be the cause of a short?

Also, with the drive sleds, there are large head mounting screws for the drives as the drive sits on a rubber grommet. But the screw thread bottoms out in the drive before the drive is secured. That was the case for all 3 of my drives. Weird design. So I put a tiny metal washer between the screw and the rubber grommet - not contacting the drive. The washer touches nothing else in the case - not even the drive sled. Just the mounting screw where it seats against the rubber grommet. But would this cause a problem?

I've yet to pull this apart yet again, and retry the 620W PSU without the faulty drive (which I now consider a dead drive). But that's next

So what's going on here? Could it just be that drive, or are these symptoms of a short somewhere else and I'm playing with fire even running this right now?

message edited by Tim_B

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April 6, 2015 at 11:28:20
Just to check my understanding, presumably after the computer suddenly shut down, all that follows is your attempts to work out the reason.

It is hard to imagine any outside reason for the HD puffing out smoke, except the it had just decided to fail and most likely that is what caused your issue. Failures of this type often exhibit more minor symptoms just before they totally fail.

It is rare for electrical problems to cause overheating unless some item is seriously defective.

Wait for some more opinions though.

Always pop back and let us know the outcome - thanks

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April 6, 2015 at 13:37:45
"I've never heard of an HDD causing an electrical problem, shutting a system down and then preventing it from starting"

Yes, a bad HDD can cause all sorts of problems. But being that you modded the chassis by drilling a hole & used screws that are too long to mount the HDD & then used washers to "shorten" them, it's anybody's guess as to what the cause of the HDD failure might be.

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April 6, 2015 at 14:52:24
✔ Best Answer
First, the hard drive is obviously dead now. The long screws MIGHT have caused a short but I remember that all HD screw holes are closed on the bottoms so a long screw should not have been able to short anything unless forced past the normal stopping point and deforming the HD's case into internal components.
Being that you switched around the hard drives a couple of times (from what I read), you might have bent a component on the drive's board or somehow got something metal sticking to the drive's board, or possibly one of those washers slipped in behind the board on the drive, any of which could have caused the short that shut you down and eventually killed the drive.
If the drive does not appear to be 'tampered with' you may be able to send it back to WD under warranty and they will probably just need to change out the board.
I doubt that anything else was affected if all else works now.

You have to be a little bit crazy to keep you from going insane.

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April 6, 2015 at 19:27:17
@ Derek
"Just to check my understanding, presumably after the computer suddenly shut down, all that follows is your attempts to work out the reason."

Yes that's right.

@ riider
I didn't actually use screws that were too long, I used the screws provided by Fractal Design that came with the case. You can't use a standard drive screw because the drive sleds have large rubber grommets, in large diameter holes - their attempt to reduce vibration. So they give you these drive screws with xtra large diameter heads,and a pass through portion before the threads start, so that the screw head won't slip through the grommets. Problem is that when you tighten them to just normal pressure that you would for any drive, the screw tightens (bottoms out) before it actually secures the drive to the sled. You can move the drive side to side and lift it slightly - a millimeter or two of play.It's really a design flaw. It was this way with all three 3.5" HDD's I mounted. So, to secure the drive I added the washers. I initially tried various plastic tap washers, but they were too much. The threads barely caught. So I used small metal ones. I did this all out of the case, then slid the tool-less drive sled back into the drive bay once the drive was seated properly. This isn't a problem with 2.5" SSD's as there is of course no need for anti vibration grommets - they have standard mounting holes with standard screws.

"Yes, a bad HDD can cause all sorts of problems." After running through all of this again, and again, I'm leaning toward this as the problem.

@ Fingers
Thanks, good things to check
With the washers, I had to scrounge to find 12 small identical ones - 4 for each drive & 3 drives - so it wasn't like there were any washers left over that could have disappeared and contacted something.

After thinking about it this afternoon, I came to the conclusion that the problem just couldn't have been the drive attachment with the screw issue. The screw is metal, the washer is metal. Neither touch anything other than the drive and a rubber grommet separates the washer from contacting the drive directly, or the sled. I've done maybe only 9 or 10 builds in my 50 years, but I've replaced many drives, so I feel confident with screwing drives in to just snug and not over tightening.

After pulling the drive out, I inspected it closely with a magnifying glass with a light on it, and could see nothing. But, as you said, it's dead. From the exterior it looks pristine. No visible black mark on the contacts from the electrical spark \ short..So as far as warrantying the drive goes, it should be no problem. It's only 11 months old. All the data is backed up.

I was gone all day, so I've only just been running the computer for about an hour again, No more issues so far. So I guess all this points to the drive itself as the issue.

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April 6, 2015 at 22:13:31
Are you sure you got all the metal filings out of the case after drilling the hole? I've occasionalliy had to use a drill to make things fit and know it can be hard to get them all out.

About the drives not being tight even thought the screws are all the way in; as far as I know all hard drive screw threads are 6-32 (SAE). Optical drive screws are 3 mm. So make sure you're using the right size screws. The 3 mm optical drive screws won't tighten to hold a hard drive.

I have seen a hard drive circuit board ruined by someone using too long a screw but the mounting holes on most drives now aren't positioned in a way that that could happen any more.

It's also possible the drive's data cable caused the problem. I suggest you replace it before attaching another drive there.

message edited by DAVEINCAPS

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April 7, 2015 at 01:12:21

I did think I got the metal fillings from drilling the screw hole, but you're right, it is a possibility. I still may pull the motherboard to have a look behind. Right now I'm putting together a previous build with components that were in boxes. I want to recheck the drives, and the PSU's by testing them both in that build. However, all evidence is pointing to the one 3TB WD drive as faulty.

The Design R4 case has a proprietary drive screw. It's impossible to mix it up. Here is a pic

The upper unthreaded shaft portion of the screw - the pass through - is to accommodate passing through the rubber grommet that sits between the drive and the drive sled. It's the only place it can be used and it's shown on a blown up schematic of the case. However, as mentioned, it is a poor design as the screw thread bottoms out before it secures the drive to the sled very well. It would be impossible to tighten it anymore without doing damage. Of that I'm %100 sure. At any rate I pulled the washers out and just let the drive sit slightly loose in the sled, but with the screws tightened in place. It's the best that can be done with what I consider a poor design.

I will pull the data cable - good suggestion. I had already inspected the sata power cables and tried various combinations and permutations of arranging them, with no differences noted.

On to build # 2

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April 7, 2015 at 06:53:00
"It would be impossible to tighten it anymore without doing damage"
Obviously difficult to properly imagine the situation but is there any scope for packing washers under the screw head, or maybe sawing the screw shorter? In the latter case using a flat file on the sawn bit followed by slight chamfering around the edge to clear away the rough bits usually works fine.

Always pop back and let us know the outcome - thanks

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April 8, 2015 at 14:14:03
To verify the hard drive is causing your computer to not start up simply disconnect the hard drive power and data cables and try again. Be sure to perform that while the computer is unplugged or the PSU is switched off, if equipped with an on/off switch.

Hard drive is NOT required to POST.

Did you use a vacuum cleaner on the computer at any point?

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April 8, 2015 at 19:12:18
It was the drive. I tried it in the second build after putting it together, and everything ran as normal - except the drive is now unrecognized.Same in both my machines - the AMD \ ASUS mobo \ Cooler Master PSU build I just put together, and my original Intel \ Gigabyte mobo \ Seasonic PSU build. So after the electrical spark,, it definitely killed the drive - and the no start \ no power on problem. The drive is under warranty so it goes back.

@OntehHill - thanks, maybe it wasn't clear in the post, but that's what I did to eventually diagnose it.

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April 9, 2015 at 03:10:41
OK , good luck with the return and thanks for popping back to let us know.

Always pop back and let us know the outcome - thanks

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