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An original, first generation GA-P35-DS3 shipped to vendors in June, 2007.  (Source: toukatu.blogzine.jp)

In the chart above, the red line represents the field strength limit against frequency. On a six frequency sample, this particular motherboard demonstrated a field almost 7dBuV above the EU directive.  (Source: Taiwan Eletronics Testing Center)
Motherboard manufacturers will do anything to save a buck, and they'll do it at the expense of your electronics

Ever wonder what that big FCC logo on your computer means? Most people would tell you the U.S. Federal Communications Commission operates like an all-seeing, all-knowing electronic shield; protecting America from harmful radiation and interference.

The reality, of course, is quite different.  To better illustrate this, we've traveled the history of one motherboard.  This motherboard, while rather unimportant in the scope of all things silicon, became rather important when a few engineers started asking the right question.

EMI, or electromagnetic interference, is a broad term that encompasses any type of interference that can disrupt, obstruct or simply degrade electronic transmissions.  Some forms of propagated radiation are intentional, such as radios; in other cases propagated radiation is completely unintentional. When unwanted electromagnetic radiation is received by an electronic device that doesn't have sufficient shielding, electromagnetic fields can disrupt the intended fields. 

The Gigabyte GA-P35-DS3 started just like almost any other motherboard.  A reference design was sent from Intel to Gigabyte's design center in Taiwan.  The test boards were wave-soldered outside of Taipei and production boards were shipped to channels as soon as physically possible to snag some of those "first-to-market" sales.

Even though the motherboard boldly wears CE and FCC markings, this device became one more component that slipped through the cracks.  It was later discovered that not only did this motherboard fail European and U.S. electromagnetic interference regulations, but that tens of thousands of the motherboards shipped months ago.

A Taiwanese motherboard engineer, who wished to remain anonymous, claims the world of EMI certification runs more lax than consumers would believe.  "If we claim to pass FCC and in actuality we do not, it's just a conscience problem." 

The engineer continues, "Some manufacturers put the FCC logo on their product even though they don't send in to any lab.  If they are lucky, they go by. If they are unlucky, they get fined by the government or in some serious case, issue a product recall." 

Conversations with other representatives reveal even in the instances of serious violation, vendors receive little official recourse. 

The most expensive Taipei-based testing facility costs approximately 2,000 USD for full electromagnetic compliance testing. 

The European Union dictates the acceptable EMI levels for products distributed in Europe.  Manufacturers that pass the European Union's EMI directive may brand the CE marking on their products. The U.S. Federal Communications Commission has a separate set of EMI standards that devices must pass in order to brand the FCC logo.

In the U.S., the Office of Engineering and Technology (OET) mandates the FCC EMI limits. Title 47, Part 15 of the Code of Federal Regulations details the acceptable EMI limits for electronic devices in the United States as follows:

30~88MHz     30dBuV
88~216MHz    33.5dBuV
216~960MHz   36dBuV
>960MHz      44dBuV  
The European counterpart directive follows slightly different limit ranges:
125~175MHz  30dBuV
250~625MHz  37dBuV
For example, all electronic devices sold in the U.S. cannot produce an electrical field with strength of more than 33.5 dB microvolts per meter at 90 MHz.  Since fields are measured in decibel units, an increase of 3 dB means the field strength has approximately doubled.

Even after sitting on store shelves the better part of three months, someone eventually noticed the Gigabyte GA-P35-DS3 acted a tad noisy -- electronically.  The FCC reserves the right to test devices at the expense of the vendor, though it rarely independently tests devices unless a complaint has been filed.

Unfortunately for the GA-P35-DS3, several complaints were filed.  The Electronics Testing Center, Taiwan, began an electromagnetic compliance test; three Gigabyte GA-P35-DS3 motherboards were hand-submitted to the lab.  Three out of three test results failed to stay "in bounds" for Taiwanese and EU regulation (PDF); two out of three failed to stay within U.S. FCC regulation.

That apparently has not enticed the Taiwanese government to order a recall or reparations.  One engineer close to the product's development states, "At least the board was tested."

So what's special about the GA-P35-DS3?  Nothing, it would seem, other than the fact that it carries markings from both the FCC and European Union claiming it does pass regulation.  Some would argue even this particular trait does not lend itself to individuality.

Gigabyte spokesperson Colin Brix denies all claims that the GA-P35-DS3 fails to meet EMC standards.  "The tests conducted at ETC are not complete," he states.  As proof, Brix shared the results of similar EMC testing conducted by QuieTek (PDF), another Taiwan-based laboratory.  All motherboard tests in this round of testing were done with the motherboard in a chasis.

Ransom Cheng, a former employee at a large motherboard vendor, explains, "The testing in Taiwan is very poor.  Only a few sample ranges are taken and the benefit of [the] doubt is always given to the vendor."  Cheng concludes, "It's not good for anyone to waste boards."

At one time, the GA-P35-DS3 was available at U.S. and European merchants, but today is no longer available in North America.  Gigabyte public relations manager Angela Lan claims the GA-P35-DS3 was removed from American markets due to its lack of RAID functionality.


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By kilkennycat on 9/26/2007 2:31:42 PM , Rating: 2
I have no reason to believe that the microwave is faulty. I believe that it is typical of the higher-energy microwave ovens. And the fact that I have not been able to easily find RF-spectral limits on microwave ovens in a Google search makes me very suspicious. Anyway, the microwave apparently works perfectly; never needed servicing. The radiation issue has existed from the beginning, noticeable on the cordless-phone, but has become potentially far more objectionable with the more continuous and higher-bandwidth usage of my RF network connection... I have recently upgraded to 3MBit DSL. BTW, I only use the microwave for short bursts of heating, maximum 5-10 minutes. Some research by you as to whether domestic microwave ovens are supposedly regulated by the FCC with regard to a maximum spectral energy profiles might end up with some interesting and revealing information. I will send you the full model details on this specific microwave via email.


By mars777 on 9/27/2007 4:53:33 AM , Rating: 2
It has to do with the fact that allowed EMI radiation on 2.4Mhz is so high that it interferes with the 2.4Mhz of 802.11g wifi.

Yes. The microwave ovens have the exact same Hz range of wifi. And your problem is not unique. It happens to everbody on earth who has the oven close to the router or receiver, or worse, between them.


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