Understanding Apple EMC Numbers
EMC numbers identify every iMac, MacBook, Mac mini and just about every other Apple computer. Many people don’t fully know what they mean, or don’t know they exist at all, but they can be an great method of IDing Apple devices. And in a world where Apple insists on using the same model number for six different computers (I’m looking at you A1278), understanding how to use EMC numbers is downright necessary.
What are EMC numbers?
EMC numbers are often overlooked or unheard of, but are very useful when used properly. EMC stands for “Electromagnetic Compatibility” and, unfortunately, seems more complex than necessary. Essentially, EMC numbers refer to the ability of electronic equipment to be a ‘good electromagnetic neighbor’, without causing or being susceptible to electromagnetic interference.
Are you confused yet? Don’t stress, all you need to know is that EMC numbers are located on almost every iMac, MacBook, MacBook Pro, and MacBook Air (with the exception of certain older models) and are most commonly used for identification purposes.
What makes EMC Numbers useful.
Apple doesn’t seem to be a fan of the identification methods used by, well basically the entire electronics manufacturing community. Remember, they like to “think different”, but in their goal of simplicity, they don’t really make it easy on you when you’re trying to figure out which upgrade is compatible with your computer, or which part you need to replace when something goes wrong.
The model number, the gold standard of electronics identification. Don’t even bother trying to use it to pinpoint which device you have because Apple likes to use the same model numbers over and over again.
On the other hand, the EMC number is a relatively unique number, usually changing with each official release of a product line. The official release year of each device (always prefaced with Early, Mid, or Late) is also a reliable way to identify an Apple computer, but mysteriously the release year is nowhere to be found on the exterior of the device. Or the interior for that matter.
It is important to note that the EMC number is not a perfect identifier either. It’s not always printed on the exterior of the device, and there isn’t always a unique EMC number for each release of a device. And if you go back far enough into Apple’s product lines, there are no published EMC numbers at all. But short of the serial number, there are no perfect identifiers in Apple land, and the EMC number makes for a better method of identification than most.
Where are EMC Numbers located?
Haven’t seen one before? You can’t find them in your About This Mac window. Despite being so useful, they’re inconveniently located and typically printed in small text. And you won’t find any handy resources on Apple’s site to explain what they mean or which computers were assigned which EMC number.
Elusive? Yes. Distinguishable? Yes! These subtle-little-buggers are found hiding under the bottom case, inside the battery bay or simply printed in plain sight on the back, near the serial and model numbers. Here is a short list of popular Mac series where we’ve found the location of these numbers:
- On the back of the housing, sometimes underneath the hinged stand.
- Underneath the "foot" stand. The surface pointing towards your table.
- On the underside of the MacBook laptop, near the model/serial number.
- Inside the battery bay of MacBook laptops with removable batteries.
- On the underside of the MacBook Pro laptop, near the model/serial number.
- Inside the battery bay of MacBook Pro laptops with removable batteries.
- On the underside of the MacBook Air, near the model/serial number.
Help us improve future content by leaving feedback, comments, or suggestions!
Show Your Love For This Post
With macOS 10.13, otherwise known as High Sierra, Apple introduced an ambitious EFI update. Several of the changes include: the introduction of the Apple File System, support for NVMe drives, and the usual batch of security updates. However, these EFI updates can cause some unwanted behavior when you test your Apple computer’s memory. At Beetstech, we use a long-time industry standard, MemTest86 to perform a comprehensive test of each computer’s RAM.
But never the type to blindly accept test results, strange testing outcomes led us to discover a bug in MemTest86 affecting computers running the new EFI firmware. In short, the newly updated EFI causes MemTest86 to incorrectly fail certain tests. But there is good news: while normal operation of MemTest86 is limited under these new EFI updates, we also discovered some simple workarounds for testing your Apple’s memory in MemTest86.
So let’s dive into how we discovered the MemTest bug, devised a reliable work-around, and get into some nitty gritty details of MemTest86 operation.
They go by “jumper pads”, “short-circuit pads”, “power pads”, and “power-on pads”. Whatever you call them, there are two bits of metal on your MacBook logic board that can force your laptop to boot up, even if the power button won’t do the trick.
Anywhere premium products are produced, there are unsavory folks trying to make a quick buck selling cheap knockoffs. It happens in every industry, from clothes to food to tech. But in recent years, counterfeit electronics have surpassed nearly all other categories of counterfeit goods by dollar value, and Apple, being the de facto high-end electronics manufacturer, makes for a prime target.
But you’d never be caught buying counterfeit electronics, because you can tell the difference, can’t you?
Remember the good ol’ days of carrying a spare battery, upgrading your own RAM, maybe even adding a second hard drive? If you’re an Apple user, those luxuries may be behind us, but upgrading your own solid state drive is still a privilege the Apple overlords allow us to have, for now that is.
Despite retaining the ability to upgrade your own SSD, ever since Apple introduced their proprietary “blade” SSDs in 2010, the task hasn’t been as simple as it once was. Apple talks up read and write speeds, but they rarely dive into the nitty gritty details of the technology behind the SSDs they use — drives specially designed only for Apple computers.
After countless questions, both from customers and our own staff, we decided to start our own investigation into the hardware involved. You have to be a bit of a private eye to uncover the secrets behind these drives, and the deeper we looked, the more surprises we found.
Owners of a Unibody MacBook Pro laptop are probably already aware that failure of the hard drive flex cable is a common issue. While it affects just about the entire Unibody lineup, the Mid 2012 MacBook Pro 13″ (Model A1278) is especially prone to this type of failure.
What is it that makes the Mid 2012 release special in this regard? A design flaw in the flex cable that seems to be compounded by the properties of the aluminum housing.
Our repair services department noticed this issue when they’d replace a bad cable, only to have the customer return a few months later with another bad cable. And possibly again with yet another bad cable. It didn’t matter if we used a used cable or a new cable in the replacement. Customers kept returning with the same persistent issue. We had to figure out what was causing the issue and find a solution.