Wireless intereference...from my motherboard?

[artoodeeto]

Hey guys, weird issue here. I have a Linksys wireless G router with DDWRT installed. I recently upgraded my system to a Gigabyte Ga-970 motherboard with an AMD 8-core processor. Prior to this upgrade I didn't have wireless issues. I only upgraded my RAM, motherboard and processor. I retained the same video card and hard drives.

Since the upgrade, I've noticed high-pitched electronic "squealing' periodically coming from my machine, and have noticed apparent wireless interference. My desktop is hooked up to the router via a wired connection which always works, but I've noticed that while the desktop is on, my work laptop, my wife's laptop, my wife's iPhone, my piano computer (wireless USB adapter) and our DVD player that streams Netflix wirelessly all have periodic connection issues. Typically when these other devices can't connect to the internet via the wireless, as soon as I turn off my desktop they all magically start working. And it bears repeating that my desktop doesn't experience these issues, which leads me to believe my motherboard is putting out some kind of RF interference that screws up the router signal.

Anyone ever experience anything like this? It doesn't happen consistently, but it's getting REALLY annoying...

[slaveofconvention]

Electric motors are a big potential source of interferance - did you replace your CPU heatsink (might be the fan)

[artoodeeto]

the system's water cooled. Didn't change any of those components either - still using the same rad, fans, pump, and waterblocks.

And that electronic squealing I mentioned is definitely coming from the motherboard. I've had video cards do that in the past too, but in my old setup my GTX285 that I'm still using didn't make noise.

[TLHarrell]

Sounds like a bad cap. RMA the board.

[artoodeeto]

dang...it's well outside the store return policy timeframe...I'll have to contact gigabyte support and see if I can switch it out.

*edit - contacted them -we'll see if/when they respond...

[Twigsoffury]

Is spread spectrum enabled in the bios? and whats the tolerance?


hows the continuity of the ground on your outlet that the computer is plugged into?

[artoodeeto]

No idea on either of those, but let's put it this way - prior to switching motherboards, the wireless never had an issue.

As for spread spectrum - is that something in the router or my mainboard...? It doesn't sound familiar.

[artoodeeto]

Gotta love tech support - the response to my fairly detailed description: "are you sure it's the board? check the video card fan." this is AFTER I told them my video card is liquid cooled and doesn't have a fan... oy.... :rolleyes:

[TLHarrell]

They're just braindead low tier tech support zombies. They only know how to follow the script. Their script assumes you're the normal deadbeat barely knows how to turn a screwdriver type user. If the guy who has to use 75% of his mental ability to keep breathing can't help in a matter of 90 seconds, as for the next tier support.

[artoodeeto]

Yeah, I've experienced this many times before. I'm reminded of a time I called my ISP because of an issue with my cable modem, and first thing I said was I'd already tried unplugging it and plugging it back in several times to no avail. Their (initial) response? Try it again. Gee...if it hasn't worked the last 3 times, why would it suddenly magically work this time? :facepalm: hopefully in my present predicament I'll now get the next tier...

[TLHarrell]

Lunacy: Trying the same thing several times over, hoping for a different result. They're lunatics.

[artoodeeto]

They gave me info to RMA the board. Only issue is it looks like I'll be without my machine while they test it. Good part though is I *may* be able to drop it off instead of shipping it - they're located about 60 miles from where I live, and my work regularly takes me out close to them. Here's hopin'...

[artoodeeto]

Well, I got RMA info from Gigabyte...but then I thought "hey, maybe I'll try moving the router to a higher position (it was near the floor). that'll be WAY easier than taking apart the computer." Seems to be working, but I'll have to give it a few more days before I declare it successful...

*edit - nope. It worked better for a couple days, but today reverted to previous behaviour. commence grumbling....

[artoodeeto]

Apparently I'm not the only one:
http://www.overclock.net/t/957608/possible-for-mobo-to-be-causing-my-wireless-interference

*edit - found a thread that recommended the following changes:
• Lower the MTU (Maximum Transmission Unit) from 1500 to 1492 or less
• Adjust the following advanced wireless settings:
◦ Lower the beacon interval from 100 to 50
◦ Lower the fragmentation threshold from 2346 to 2306
◦ Lower the RTS threshold from 2347 to 2304
Also changed the channel from auto to channel 9.

Seems to be working...for the moment anyway...

[Konrad]

I think if you monitor and log all the temps and rpms in your box you can correlate if anything activates/deactivates or changes speed during these "squealing" moments. It could be internal mechanisms beyond your control, like a stepper motor on one of the HDDs which only kicks in whenever the OS orders a cache rewrite. Is there anything you can do which deliberately reproduces this squealing on demand? If the squeal does indeed cause EMI with your WiFi then duplicating it with the metal chassis cover off should intensify the problem, shielding or moving or reorienting the computer might be enough to diminish the problem. You could try moving the (computer-side) WiFi antenna, it could be in a bad spot or the wire could be stretched or threaded across something noisy.

I was going to suggest adjusting the BIOS spread spectrum settings ... already done.

I would try swapping the PSU first. Then systematically removing drives and fans until the problem is isolated. If it continues to persist then it's gotta be bad mobo or dirty power line (your house wiring could be acting as an antenna or have some kind of harmonic interference caused by anything else on the circuit, even outside your property). People like to blame the electrolytics, but it could cracked traces, bad solder points, any kind of failed component, or even just bad design. I would inspect all the caps, inspect all the inductors, check that all the power and I/O connectors are clean, and - importantly - confirm that there isn't any sort of ground fault. Oscillating noise is almost always mechanical, intermittent noise usually indicates component overheat or failure. If you have a stethoscope, IR thermometer, microwave leak detector, radiated wattmeter/dipmeter or other items of the sort then you can use them to troubleshoot with great precision during squealing operation.

You can use old antenna tricks to "focus" your WiFi a bit. Lacking optimum-calculated parabolic reflectors and such you could just try some quick experiments with metal bowls and tinfoil. Licensed ham radio folks are permitted to rip out the puny ducky antennae and plug the WiFi box into serious transmission tower stuff, extending their WiFi coverage by a few kilometers lol.

[artoodeeto]

Is there anything you can do which deliberately reproduces this squealing on demand?

Seems to mostly happen when I'm doing things like scrolling web pages, but it'll also happen when the computer is just idling.


If the squeal does indeed cause EMI with your WiFi then duplicating it with the metal chassis cover off should intensify the problem, shielding or moving or reorienting the computer might be enough to diminish the problem. You could try moving the (computer-side) WiFi antenna, it could be in a bad spot or the wire could be stretched or threaded across something noisy.

Can't remove the metal chassis as there isn't one - the motherboard's in my sandcrawler computer, which is mostly MDF. The mobo is mounted on a metal tray, but that's an aspect that hasn't changed since I first built this case 5 years ago. Also, the machine is hardwired to the router - it's our DVD player, laptops, and my wife's iPhone that have the connection issues.


I would try swapping the PSU first. Then systematically removing drives and fans until the problem is isolated. If it continues to persist then it's gotta be bad mobo or dirty power line (your house wiring could be acting as an antenna or have some kind of harmonic interference caused by anything else on the circuit, even outside your property).

Can't swap the PSU - I've kept it the same through several upgrades, and it's completely dismantled from its original case and incorporated into the model portion of the computer. Also, I had zero issues prior to switching out the motherboard, processor, and RAM. Everything else (PSU, video card, fans, pump, radiator, waterblocks, SSD and 2.5" standard HD, power plugs that everything is hooked up to) is exactly the same as before the upgrade. That's why I'm thinking it's the motherboard - it's the only major thing that changed and, given its relative complexity of parts compared to the CPU and RAM, in my mind that makes it the most likely culprit. And it's most likely only interfering with one wireless channel.

Making those wireless router changes seems to have fixed it: prior to changing those settings, my piano computer in the living room, my DVD player, my wife's iPhone, and both laptops were having problems yesterday. As soon as I changed those settings on the router, all of a sudden internet was working on all devices. :up: Need to give it a few days though before I declare it completely successful.

I've been reluctant to RMA the board for a couple reasons: it'll be a HUGE PITA to take the machine apart. And I might take it out to Gigabyte, have them look at it and not be able to find any issues with it. It's an intermittent problem on (most likely) one or two of the wireless channels, which would make replicating the issue more difficult. I'll go that route if I continue to experience problems.