New computer systems extra susceptible to static

I have recently upgraded 2 computer at our office. They each have a new Corsair 88R case. The problem is that these new machine are extremely susceptible to static. Most of the time, when the user touches the case -- even to [up]plug a USB device, the machine freezes. No keyboard, no mouse, no activity. A hard reset is required. These users' former computers were in the same location and exhibited no such problems. On tech I talked to said I should have used the copper-colored stand-offs to mount the MOBO to the case. Another tech said they were only for MOBOs that had extra mount points beyond the arched "bumps" in the case for mounting. I'm searching for ideas as to why these computers are having such a problem with static whereas their predecessors did not.

Ideas?
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jmarkfoleyAsked:
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nobusConnect With a Mentor Commented:
your thinking is wrong - why do you not have static on other systems then ?
just test what i suggest - yes?
Anyway - the only good solution is to eliminate the static - so it can't build up; do you have floor mats or carpets? replace them with anti static ones - or put the desks on such mats - connected to gnd
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Wayne88Connect With a Mentor Commented:
I never used this specific case before but static problems are normally due to bad or insufficient ground contacts.  

First thing to check is if this PC connected to a power bar or UPS.  Try eliminating them by plugging it directly to the wall socket then test.  If still a problem, try plugging it to a different wall socket.

Failing that, you can try is to install a wire connector that will surely connect the mobo to the case by using the screw mount points.  You can use wire connectors like the one below if you wish.  Connect one end to a mobo screw point which has a copper contact then the other end to a case screw with direct metal contact.  Do so with caution to ensure you don't expose the connectors to any other circuit on the motherboard which can fry it.

plug.jpg
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nobusCommented:
it looks like a fairly normal case to mif you take the AC cable out, do you measure 0 ohm between the earth pin of the connector, and the chassis of your case? if not, there is a grounding problem, either with motherboard or PSU - can you tes t with another one?
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dbruntonCommented:
>>  One tech I talked to said I should have used the copper-colored stand-offs to mount the MOBO to the case

How did you mount the MOBO to the case?

Normally you use the standoffs (and these are usually metal) that come with the case.  In some installs you must take care that you don't use certain holes with metal stand-offs and use plastic ones instead.  I've struck the odd motherboard like that.
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jmarkfoleyAuthor Commented:
Wayne88:
I never used this specific case before but static problems are normally due to bad or insufficient ground contacts.
Corsair is a pretty well-known vendor and they make power supplies as well. I would hope it's not the case that's defective. Still, this is the 2nd system using this case with which I've had this issue.
First thing to check is if this PC connected to a power bar or UPS.  Try eliminating them by plugging it directly to the wall socket then test.  If still a problem, try plugging it to a different wall socket.
It is plugged into a UPS, but the previous Dell computer was plugged into the same UPS. I don't have easy access to the wall socket, but I can access a power strip. Although I hate to leave the computer without a UPS, I can try that.
Failing that, you can try is to install a wire connector that will surely connect the mobo to the case by using the screw mount points.
Something to try, but complex enough that it will be a last resort.

nobus:
if you take the AC cable out, do you measure 0 ohm between the earth pin of the connector, and the chassis of your case?
Where are you suggesting I measure? Do you mean unplug the AC cable and measure between the ground of the plug and the chassis?

dbrunton:
How did you mount the MOBO to the case?

Normally you use the standoffs (and these are usually metal) that come with the case.  In some installs you must take care that you don't use certain holes with metal stand-offs and use plastic ones instead.  I've struck the odd motherboard like that.
This case had arched "bumps" from the wall of the case, tapped for screws. They included a few metal standoffs, but no plastic ones. I mounted the MOBO to the metal bumps, no stand-offs. As I mention, one tech told me that's how it should be done and the metal stand-offs are just for larger MOBOs that need additional support where there are no "bumps". Using just the bumps and no stand-offs, the rear connectors line up. With stand-offs I think the MOBO would be too high.

What about the feet? I assume the case should be "grounded" as in grounded with the floor/carpet so as to eliminate static potentials between the case and the environment (e.g. user's finger). If so, perhaps I need a different set of feet? Or is that not true and it should simply be grounded to the electrical system al la Nobus' line of thinking?
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dbruntonConnect With a Mentor Commented:
>>  As I mention, one tech told me that's how it should be done and the metal stand-offs are just for larger MOBOs that need additional support where there are no "bumps".

Yep.

I'm not sure this is a static problem but an earthing or shorting problem.  Could it be possible to insert a thin plastic (or paper) washer between the board and these bumps in the case tray?  The board will still be earthed by the screw going through the top of the board into the bump but any possible shorting problem between the base of the board and the bump will be eliminated.  I can remember doing this on a very old 286 (could have been older) with paper washers.

And no stand-offs unless plastic if the board needs extra support and has holes where there are no supporting bumps in the case tray.
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jmarkfoleyAuthor Commented:
dbrunton:
Could it be possible to insert a thin plastic (or paper) washer between the board and these bumps in the case tray?
I thought of that. There used to be thin "washers" made out of an orangey cardboard-like material. Perhaps I can find some at our local electronics/computer store. I'll check.
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nobusCommented:
>>  Where are you suggesting I measure? Do you mean unplug the AC cable and measure between the ground of the plug and the chassis?
   <<   yes that's wghat i asked; next step is measure from chassis gnd to wall socket ground
you can also measure the voltage between them
or connect a wire from chassis to ground socket and test
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jmarkfoleyAuthor Commented:
My thinking is this: I don't think there is a grounding problem between the computer and the building ground (per nobus' idea). Rather, I think there is a static potential difference between the human and the computer/building. If the human touches a door knob, he'll get a zap. Since the MOBO is grounded to the case, and the computer/case is grounded to the building via the power cord, there is nothing that can be done about the differential with the human.

Upon further inspection the one case is a Thermaltake, not Corsair. So, the computers giving me this problem are NOT the same case manufacturer. So, why did the previous computers not have this problem? Perhaps because one of them was a Dell. Dell and HP have great, tank-like cases with lots of little removable trays and apparently lots of shielding. Perhaps those cases were designed to help dissipate environmental static? Too bad I had to put the new MOBO in a new case. Dell and HP seem to make an effort to create cases and MOBOs that are of custom dimensions and do not fit a "standard" MOBO. Also, their front-panel connectors are in an unmarked header which would required more effort/cost to trace and re-pin that just getting a new case.

Anyway, perhaps my solution is to get an-anti static floor mat which might help dissipate user potential when trod upon?
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jmarkfoleyAuthor Commented:
I did measure the voltage between the earth-pin of the power cable and the chassis and also to the ground socket of the wall outlet -- on both computers. No ohms. I doubted this was a problem since it seemed unlikely that two different, recently replaced computers, with two different cases and two different new power supplies would both exhibit this "static" problem due to coincidentally faulty power supplies and/or grounding to the motherboard. I think the static floormat is the best way to deal with this problem.
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nobusCommented:
what did you measure?  first you say voltage, then no ohms...
i never said it was a pc fault - you start somewhere - then continue
but maybe i was n ot clear;  you take the ac plug out of the pc and measure on the ground of the plug to the wall ground
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jmarkfoleyAuthor Commented:
Nobus - yes, sorry that's what I did. I shouldn't have used the term "voltage". I was using a multi-meter which I often call a "voltmeter", incorrectly.

Anyway, I just installed another computer with the same Corsair 88R case, new Corsair power supply, same AMD FX-8530 processor and same M5A78L-M\ PLUS\ USB3 MOBO, for another user. I was touching the case and plugging/unplugging USB devices frequently. Never had a static problem. This is now mid-May, not dead-of-Winter, and from experience I know that static problems are exacerbated in the Winter. I'm going to conclude this is an environmental static problem, not a problem with any of the hardware. I will recommend to the Powers-That-Be that anti-static mats be installed for all offices.
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nobusCommented:
and what happens if you put the Original back?  if still static,  - measure on the PC AC plug from ground to case grnd - should be 0 ohm
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jmarkfoleyAuthor Commented:
The original computers precipitating this post are no longer giving me the static issues. I'm going to recommend static mats and be done with it.
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