I have a possible grounding issue

[Dadofamunky]

I contacted Asus chat support and they were actually very helpful. I may have a problem with the Intel motherboard in my sig, but it seems more likely that my mobo is having a grounding problem with the standoffs that fasten the board to the motherboard trey on the Lian-Li case. The Asus people think my terrible audio stuttering (in iTunes, Blu-Ray, sound editing, etc...) may be due to this. I think it's very possible, because the problem has been somewhat intermittent. I've gone so far as to disable the motherboard sound chip, remove the drivers (and the VIDEO CARD drivers too) and install a PCI sound card. Same. Exact. Problem. I've swapped memory. My disk performance is excellent.

I have gone round and round with this for months. A grounding problem makes sense given what I've seen. Fortunately none of my hardware appears to be damaged in any way (crossing fingers).

So this weekend I have to break my system down and essentially run it outside of the case, off the trey, on a non-conductive surface. (Because of my small case, and small desk area, this is a REAL pain in the ass.) Then I have to find a way to ground-insulate the motherboard from the standoffs.

My question is: what would be the best way to do so?

 

[Zepper]

First, you can't really insulate the mobo from the standoffs (the proper mounting holes are thru-tinned inside and the lands and tinning in the hole are all connected to the ground plane (you can check this for yourself with any Ohm meter) unless you get nylon standoffs and nylon screws - best is to make sure you are getting good grounds at ONLY the proper mounting holes. Make sure you are using standoffs at ONLY the designated mounting holes for the mobo (they will usually have shiny, tinned rings (lands) around them on both sides) and that you don't tighten too tightly as you can crush the mobo. If unsure, there should be a diagram pointing the proper holes out in the manual. Also make sure the heads of the screws you are using aren't too large and touching things they shouldn't and that they aren't so long that the mobo is loose. The case manual should point out which screws to use, but anyone with common sense should be able to decide which are appropriate for thread and length. I really don't care for the way that Lian Li uses M3 thread screws for everything. Luckily I have a large stash of parts and have some M3 screws that are short and have a large diameter head which I used in my Rocketfish instead of what L-L supplied. If I was going to keep a L-L case, I'd switch out the standoffs for ones with US #6 thread inside and out. I'd be tapping out a lot of the threaded screw holes on it for #6 screws. Short of that, I'd be looking for some short threaded M3 screws with large diameter heads for mounting the mobo. www.Cyberguys.com usually has a good assortment of small hardware - this looks like it: http://www.cyberguys.com/templ...ail.asp?productID=4423

.bh.

PS: I often use extra holes in my mobos for extra standoffs, but I use the old-school, nylon, snap-in standoffs for those like this:
http://www.excesssolutions.com/cgi-bin/category/15150 - the 4th and 9th items on this page. The nib has to be cut off the bottom unless you can get ones like the last one on the page with a proper spacing and thread. .bh.

 

[Zepper]

Oh, and if it is possible that the mobo tray is isolated from the frame of the case (anodized surfaces can be less conductive), then you may have to rig a ground strap directly from the mobo to the frame of the PSU. I'd measure the Ohms with the mobo mounted on the tray and the tray installed in the chassis, from a ground point on the mobo to the chassis of the PSU. Anything much more than zero Ohms and I'd rig the strap. I'd also measure from the frames of your drives to the chassis of the PSU and strap them too if the Ohms is much over zero. bgmicro.com sells grounding wires with a ring terminal on one end and a 1/4" female quick disconnect on the other for 5 cents each. Taking shipping cost into consideration, you may want to order more than just those. Of course, if you have some 18 ga. or larger wire kicking around, then you could make your own, but I doubt you could make one for 5 cents... I suppose just the wire with stripped and tinned ends could be used in a pinch - certainly for testing purposes.

.bh.

 

[Dadofamunky]

Zepper, thanks! I had not thought of using nylon Standoffs, etc... and unfortunately, I don't think I have a working Ohm-meter any more, so I'll have to figure something out in that regard. And thanks for that link, that is going to come in VERY handy.

 

[Zepper]

I just want to be clear. There should be a solid ground from the mobo to earth thru the PSU chassis and the drives likewise to bleed off static from the rotating masses to a true earth ground - you don't ever want to isolate the mobo from ground (unless it's a poor ground and you create another path to ground). Make sure the AC outlets you use are properly wired with a true earth ground as well. Outlet testers can be had for less than $5.00 (three LEDs show the condition), and a decent multimeter can be had for under $20. often on sale at Sears.

.bh.