CNC’d MacBook Breathes Easy

Sick of his 2011 Macbook kicking its fans into overdrive every time the temperatures started to climb, [Arthur] decided to go with the nuclear option and cut some ventilation holes into the bottom of the machine’s aluminum case. But it just so happens that he had the patience and proper tools for the job, and the final result looks good enough that you might wonder why Apple didn’t do this to begin with.

After disassembling the machine, [Arthur] used double-sided tape and a block of scrap wood to secure the Macbook’s case to the CNC, and cut out some very slick looking vents over where the internal CPU cooler sits. With the addition of some fine mesh he found on McMaster-Carr, foreign objects (and fingers) are prevented from getting into the Mac and messing up all that Cupertino engineering.

[Arthur] tells us that the internal temperature of his Macbook would hit as high as 102 °C (~215 °F) under load before his modification, which certainly doesn’t sound like something we’d want sitting in our laps. With the addition of his vents however, he’s now seeing an idle temperature of 45 °C to 60 °C, and a max of 82 °C.

In the end, [Arthur] is happy with the results of his modification, but he’d change a few things if he was to do it again. He’s somewhat concerned about the fact that the mesh he used for the grill isn’t non-conductive (he’s using shims of card stock internally to make sure it doesn’t touch anything inside), and he’d prefer the peace of mind of having used epoxy to secure it all together rather than super-glue. That said, it works and hasn’t fallen apart yet; basically the hallmarks of a successful hack.

It’s worth noting that [Arthur] is not the first person to struggle with the Macbook’s propensity for cooking itself alive. A few years back we covered another user who added vents to their Macbook, but not before they were forced to reflow the whole board because some of the solder joints gave up in the heat.

The Other Way to Brick a Mac Classic

Why would you build a mini Mac Classic using LEGO and a Raspberry Pi? Well, why wouldn’t you?

[Jannis Hermanns] couldn’t find a reason to control this outburst of nostalgia for the good old days of small, expensive computers and long hours spent clawing through the LEGO bin to find The Perfect Piece to finish a build. It turns out that the computer part of this replica was the easy part — it’s just an e-paper display driven by a Raspberry Pi Zero. Building the case was another matter, though.

After a parti-colored prototype with whatever bricks he had on hand, a session of LEGO Digital Designer led him to just the right combination of bricks to build an accurate case, almost. It turns out that the stock selection of bricks in LDD won’t allow for the proper proportions for the case, so he ordered the all-white bricks and busted out the Dremel. LEGO purists may want to avert their eyes from the ABS gore within, but in the end the case worked out and the whole build looks great.

Fancy a full-size Mac Classic reboot? How about this iPad docking station? Or if tiny and nostalgic is really your thing, this retro-future terminal build is pretty keen too.

[via r/raspberry_pi]

Magsafe 1 to Magsafe 2 The Cheap Way

[Klakinoumi] wanted to use their Magsafe 1 charger from 2007 with their newer Macbook Pro Retina from 2012 — but it had a Magsafe 2 port. There were a few options on the table (buy an adapter, buy a new charger, cry) but those wouldn’t do. [Klakinoumi] went with the brute force option of grinding a Magsafe 1 charger to fit Magsafe 2.

Based on the existence of passive adapters that allow Magsafe 1 chargers to work with newer laptops, we’d assume that the older chargers are probably electrically similar to the newer models. That said, it’s not our gear and we’d definitely be checking first.

With that out of the way, it’s a simple enough modification — grind away the Magsafe 1’s magnet until it fits into a Magsafe 2 port. It really is that easy. The spring-loaded pins all seem to line up with the newer port’s pads. [Klakinoumi] reports it worked successfully in their tests with 2012, 2014 and 2015 Macbooks but that it should be attempted at your own risk — good advice, as laptops ain’t cheap.

When doing this mod, consider taking care not to overheat the connector during grinding. You could both melt plastic parts of the connector, or ruin the magnet by heating it past its Curie point.

Interested in the protocol Magsafe speaks over those little golden pins? Find out here.

Fixing Bugs In A 37 Year Old Apple II Game

Emulators are a great way to reminisce about games and software from yesteryear. [Jorj Bauer] found himself doing just that back in 2002, when they decided to boot up Three Mile Island for the Apple II. It played well enough, but for some reason, crashed instantly if you happened to press the ‘7’ key. This was a problem — the game takes hours to play, and ‘7’ is the key for saving and restoring your progress. In 2002, [Jorj] was content to put up with this. But finally, enough was enough – [Jorj] set out to fix the bug in Three Mile Island once and for all.

The project is written up in three parts — the history of how [Jorj] came to play Three Mile Island and learn about Apple IIs in the first place, the problem with the game, and finally the approach to finding a solution. After first discovering the problem, [Jorj] searched online to see if it was just a bad disk image causing the problem. But every copy they found was the same. There was nothing left for it to be but problem in the binary.

Continue reading “Fixing Bugs In A 37 Year Old Apple II Game”

Top Ten Reasons Not To Buy A Fake MacBook Charger. Number Eight Will Shock You.

Yesterday, Apple showed the world how courageous they are by abandoning their entire PC market. It’s not time for a eulogy quite yet, but needless to say, Apple hardware was great, and the charger was even better. It had Magsafe, and didn’t start fires. What more could you ask for?

When it comes to fake MacBook chargers, you can ask for a lot more. [Ken Shirriff] has torn apart a number of these chargers, and his investigations allowed for an obvious pun in this post. The fake ones will make sparks thanks to the cost-saving design, and shouldn’t be used by anyone.

A genuine Apple MacBook charger is a phenomenal piece of engineering, but the fake one is not. In fact, it’s almost the simplest possible AC to DC converter. The mains power comes in, it’s chopped up into pulses, and these pulses are turned into a high-current, low-voltage output in a flyback transformer. This output is converted into DC with a few diodes, filtered, and wired into a MagSafe adapter.

The genuine MacBook charger is much more complicated. Like the cheap copy, it’s a switching power supply, but has a few features that make it much better. The genuine charger does power factor correction, uses quality caps, has real isolation on the PCB, and uses a microcontroller that’s almost as powerful (and a direct architectural descendant) as the CPU in the original Macintosh. It’s this microcontroller that kept you safe that one time you decided to lick a Magsafe connector not allowing the full 20 Volts to go through until the connector has connected. Until then, the Magsafe connector only outputs 0.6 Volts. The fake charger doesn’t do this, and when you poke the connector with a paper clip, sparks fly.

This isn’t [Ken]’s first teardown of genuine and not Apple products. He’s done iPad chargers, iPhone chargers, and other small, square, white switching power supplies. The takeaway from these teardowns is that cheap chargers are a false economy, and you probably should pony up the cash for the real version.

Re-Capping An Ancient Apple PSU

It sometimes comes as a shock when you look at a piece of hardware that you maybe bought new and still consider to be rather high-tech, and realise that it was made before someone in their mid-twenties was born. It’s the moment from that Waylon Jennings lyric, about looking in the mirror in total surprise, hair on your shoulders and age in your eyes. Yes, those people in their mid-twenties have never even heard of Waylon Jennings.

[Steve] at Big Mess o’Wires has a Mac IIsi from the early 1990s that wouldn’t power up. He’d already had the life-expired electrolytic capacitors replaced on the mainboard, so the chief suspect was the power supply. That miracle of technology was now pushing past a quarter century, and showing its age. In case anyone is tempted to say they don’t make ’em like they used to, [Steve]’s PSU should dispel the myth.

It’s easy as an electronic engineer writing this piece to think: So? Just open the lid, pop out the old ones and drop in the new, job done! But it’s also easy to forget that not everyone has the same experiences and opening up a mains PSU is something to approach with some trepidation if you’re not used to working with line power. [Steve] was new to mains PSUs and considered sending it to someone else, but decided he *should* be able to do it so set to work.

The Apple PSU is a switch-mode design. Ubiquitous today but still a higher-cost item in those days as you’ll know if you owned an earlier Commodore Amiga whose great big PSU box looked the same as but weighed ten times as much as its later siblings. In simple terms, the mains voltage is rectified to a high-voltage DC, chopped at a high frequency and sent through a small and lightweight ferrite-cored transformer to create the lower voltages. This means it has quite a few electrolytic capacitors, and some of them are significantly stressed with heat and voltage.

Forum posts on the same PSU identified three candidates for replacement – the high voltage smoothing capacitor and a couple of SMD capacitors on the PWM control board. We’d be tempted to say replace the lot while you have it open, but [Steve] set to work on these three. The smoothing cap was taken out with a vacuum desoldering gun, but he had some problems with the SMD caps. Using a hot air gun to remove them he managed to dislodge some of the other SMD components, resulting in the need for a significant cleanup and rework. We’d suggest next time forgoing the air gun and using a fine tip iron to melt each terminal in turn, the cap only has two and should be capable of being tipped up with a pair of pliers to separate each one.

So at the end of it all, he had a working Mac with a PSU that should be good for another twenty years. And he gained the confidence to recap mains power supplies.

If you are tempted to look inside a mains power supply you should not necessarily be put off by the fact it handles mains voltage as long as you treat it with respect. Don’t power it up while you have it open unless it is through an isolation transformer, and remember at all times that it can generate lethal voltages so be very careful and don’t touch it in any way while it is powered up. If in doubt, just don’t power it up at all while open. If you are concerned about high voltages remaining in capacitors when it is turned off, simply measure those voltages with your multimeter. If any remain, discharge them through a suitable resistor until you can no longer measure them. There is a lot for the curious hacker to learn within a switch mode PSU, why should the electronic engineers have all the fun!

This isn’t the first recapping story we’ve covered, and it will no doubt not be the last. Browse our recapping tag for more.

Finally, an Acceptable Use of the Apple Watch

For many of us, we remember the days of the Apple Classic Macintosh. For [Erich Styger], his days of development in Pascal and Modula-2 are long over, but he still gets warm and tingly thinking back to the classic white box we knew and loved. So he decided to 3D print a Classic Mac to use as his Apple Watch charging station.

He started with an existing model on Thingiverse and modified it to better suit his needs — sharing CAD makes the design process go ever so much faster. It consists of two parts, an outer shell that looks like a Classic Mac, and an inner structure that holds the stock charger for your Apple Watch.

The result is an adorably small Classic Mac to sit on your desk in miniature form. It’s perhaps the most acceptable use of a $1000 Apple Watch we have ever seen.

Seriously though, the Apple Watch is nicely built — just take a look at the tear-down we covered.