Thorough Macbook Charger Teardown Reveals Some Complex Circuitry

Apple has a reputation in the tech world as being overpriced, and nowhere is that perception more common than in the Hackaday comments. The standard argument, of course, is that for a device with equivalent specs, Apple charges a lot more than its competitors. That argument is not without its flaws, especially when you consider factors other than simple specs like RAM and processor speed, and take into account materials used and build quality. But, as this teardown by [Ken Shirriff] shows, Apple’s attention to detail extends beyond simply machining Macbook bodies out of aluminum.

In his teardown, [Ken Shirriff] thoroughly investigates and describes all of the components and circuitry that go into the ubiquitous Macbook charger. Why does it cost $79? Other than the MagSafe connector, what makes it any better than the charger that came with your Toshiba Satellite in the ’90s? Isn’t it just a transformer to convert AC power to DC?


[Ken Shirriff] answers all of this and more, and you may be surprised by what he found. As it turns out, the Macbook charger isn’t just a transformer in a plastic case with a fancy magnetic connector. There is a lot of high-quality circuitry involved to make the power output as clean and stable as possible, and to avoid potential damage to your Macbook that could be caused by dirty power or voltage spikes. Does it justify the costs, even with so many reported failures? That’s for you to decide, but there is no questioning that Apple put more thought into their chargers than simply converting AC to DC.

A Third Scale Mini PowerMac

We’re surrounded by tiny ARM boards running Linux, and one of the most popular things to do with these tiny yet powerful computers is case modding. We’ve seen Raspberry Pis in Game Boys, old Ataris, and even in books. [Aaron] decided it was time to fit a tiny computer inside an officially licensed bit of miniature Apple hardware and came up with the Mini PowerMac. It’s a 1/3rd scale model of an all-in-one Mac from 1996, and [Aaron] made its new hardware fit like a glove.

Instead of an old Mac modified with an LCD, or even a tiny 3D printed model like Adafruit’s Mini Mac Pi, [Aaron] is using an accessory for American Girl dolls released in 1996. This third-scale model of an all-in-one PowerPC Mac is surprisingly advanced for something that would go in a doll house. When used by American Girl dolls, it has a 3.25″ monochrome LCD that simulates the MacOS responding to mouse clicks and keypresses. If you want to see the stock tiny Mac in action, here’s a video.

The American Girl Mini Macintosh is hollow, and there’s a lot of space in this lump of plastic. [Aaron] tried to fit a Raspberry Pi in the case. A Pi wouldn’t fit. An ODROID-W did, and with a little bit of soldering, [Aaron] had a computer far more powerful than an actual PowerMac 5200. Added to this is a 3.5″ automotive rearview display, carefully mounted to the 1/3rd size screen bezel of the mini Mac.

The rest of the build is exactly what you would expect – a DC/DC step down converter, a USB hub, and a pair of dongles for WiFi and a wireless keyboard. The software for the ODROID-W is fully compatible with the Raspberry Pi, and a quick install of the Basilisk II Macintosh emulator and an installation of Mac OS 7.5.3 completed the build.

44 Mac Pros Racked Up to Replace Each Rack of 64 Mac Minis

We were delighted at a seeing 96 MacBook Pros in a rack a couple of days ago which served as testing hardware. It’s pretty cool so see a similar exquisitely executed hack that is actually in use as a production server.  imgix is a startup that provides image resizing for major web platforms. This means they need some real image processing horsepower and recently finalized a design that installs 44 Mac Pro computers in each rack. This hardware was chosen because it’s more than capable of doing the heavy lifting when it comes to image processing. And it turns out to be a much better use of rack space than the 64 Mac Minis it replaces.

Racking Mac Pro for Production


Each of the 11 R2 panels like the one shown here holds 4 Mac Pro. Cooling was the first order of business, so each panel has a grate on the right side of it for cold-air intake. This is a sealed duct through which one side of each Pro is mounted. That allows the built-in exhaust fan of the computers to cool themselves, pulling in cold air and exhausting out the opposite side.

Port access to each is provided on the front of the panel as well. Connectors are mounted on the right side of the front plate which is out of frame in this image. Power and Ethernet run out the back of the rack.

The only downside of this method is that if one computer dies you need to pull the entire rack to replace it. This represents 9% of the total rack and so imgix designed the 44-node system to deal with that kind of processing loss without taking the entire rack down for service.

Why This Bests the Mac Mini

3 racks - Linux. Mac Min, Mac Pro
3 racks – Linux. Mac Min, Mac Pro

Here you can see the three different racks that the company is using. On the left is common server equipment running Linux. In the middle is the R1 design which uses 64 Mac Minis for graphic-intensive tasks. To the right is the new R2 rack which replace the R1 design.

Obviously each Mac Pro is more powerful than a Mac Mini, but I reached out to imgix to ask about what prompt them to move away from the R1 design that hosts eight rack panes each with eight Mac Minis. [Simon Kuhn], the Director of Production, makes the point that the original rack design is a good one, but in the end there’s just too little computing power in the space of one rack to make sense.

Although physically there is room for at least twice as many Mac Mini units — by mounting them two-deep in each space — this would have caused several problems. First up is heat. Keeping the second position of computers within safe operating temperatures would have been challenging, if not impossible. The second is automated power control. The R1 racks used two sets of 48 controllable outlets to power computers and cooling fans. This is important as the outlets allow them to power cycle mis-behaving units remotely. And finally, more units means more Ethernet connections to deal with.

We having a great time looking that custom server rack setups. If you have one of your own, or a favorite which someone else built, please let us know!

[Thanks to drw72 for mentioning R2 in a comment]

96 MacBook Pros: Most Expensive Server Rack We’ve Ever Seen

Ever see a standard server rack stuffed full with 8-dozen MacBook Pros? Well now you have.

Now before the torrential downpour of anti-Mac comments come, this actually has a purpose. No seriously. Besides, what company in their right mind would spend that much money on a rack full of paperweights? Kidding.

[Steve] works for a company that designs electronics, and for a particular launch they needed to perform a lot of testing — using MacBook Pros. There are ways he could have emulated OS X on a much cheaper hardware setup, but the whole point was to test the product with Apple hardware. So he took a stroll down to the local Apple store and picked up two pallets worth. Continue reading “96 MacBook Pros: Most Expensive Server Rack We’ve Ever Seen”

Viewing A Macintosh SE’s Video On A Modern Computer

[Bbraun] has an old Macintosh SE computer. He was looking for a way to view the video output from the SE on a newer, modern computer. He ended up working out a pretty clever solution using a stm32f4discovery board.

First, the SE’s logic board was removed from its case and placed onto a desk for easier access. The discovery board was then hooked up to the SE’s processor direct slot (PDS) using normal jumper wires. The discovery board acts as a USB COM port on a newer Mac OSX computer. The discovery board watches the SE for writes to video memory. When it sees that the R/W pin goes low, it knows that a write is occurring. It then waits for /AS to go low, which indicates that an address is on the bus. The discovery board reads the address and verifies that it falls within the range of the video frame buffer. If it does, then the discovery board writes a copy of the data to a local buffer.

The OSX computer runs a simple app that can make a request to the discovery board via USB. When the board receives the request, it sends its local frame buffer data over the USB connection and back to the host. The OSX computer then displays that data in a window using CGImage. The demo video below was captured using this technique. Continue reading “Viewing A Macintosh SE’s Video On A Modern Computer”

Hackintosh Project Looks Like a Mac, Smells Like a Mac…

It’s not often that you find a Macintosh dumped out on the side of the road. [GrandpaSquarepants] was one of the lucky individuals that did. Being the good friend that he is, he made his roomy carry the 50 lb behemoth back to their apartment. Not surprisingly, the machine didn’t boot up and ended up sitting around the apartment for a few years.

HackintoshFast forward from 2012 to present day and [G.S.] decided it was time to do something with that G5. That “something” wasn’t about fixing it. Instead, it was gutted to turn it into a Macintosh-cased Hackintosh. If you’re unfamiliar with Hackintosh, it’s a term used to describe a project that gets Mac OS to run on non-Apple hardware.

[G.S.] could have just crammed everything into the G5 case and called it a day but he decided to spend the time to make it look supremely presentable. The case was significantly modified to fit the non-Apple computer components, including the addition of a custom rear panel made from aluminum to mount the power supply, cooling fan and to allow access to the motherboard connectors. Take a close look; there are two CPU coolers in there. It was such a close fit that there is only 2.6mm (.1 inch) of clearance between the cooler and the case.

Two Dell U2415 monitors and an Apple wireless keyboard and mouse make up the rest of the setup. Overall, [G.S.] is happy with the final outcome of his project, well… except for the Apple mouse. He says that has got to go!

[via reddit]

Reflowing an Entire MacBook Pro

[Sterling]’s MacBook Pro has a propensity to heat up at times. Some of this overheating is due to to what he uses his Mac for – gaming and making music. A larger part of this overheating is that this laptop is a consumer electronics device – it’s going to die sooner or later. One day in March, this laptop bit the bullet, and that’s where this story gets interesting.

Before the MacBook died, [Sterling] was logging temps between 80 and 90ºC, with a maximum of 102º. The simple fixes, compressed air, a laptop stand, and running the fans full blast all the time didn’t help. When the laptop died, [Sterling] was pretty sure some solder joints came loose. Sending the logic board off to a place that specializes in reflowing would take weeks. A more drastic plan of attack was necessary.

[Sterling] disconnected all the wires, connectors, and heat sinks and preheated his oven to 340º F. The logic board was placed on a cookie tray and stuffed into the oven for seven long minutes. Thermal paste was reapplied, heat sinks reinstalled, connectors connected, and the machine booted. It worked great for about eight months with temperatures averaging around 60 or 70º C.

Two weeks ago, the laptop died again. This time it was reflowed with a heat gun and ran for about an hour. The third attempt was the cookie sheet again, only this time [Sterling] added something. Speed holes. Or vents, or whatever else you want to call them.

Now there’s a noticeably increased airflow in the Mac, much better than before. Average temps are back down to 40 or 50º C, lower than they were with just a reflow. The jury is still out if this new addition can go the distance, but with any luck, this mod might make it through 2015.

Thanks [Doug] for the tip.