Project Airbag: MacBook Air Rev. A USB SSD + Sound Fix


I’m back again with another project! This one is another relatively short one, but it’s full of hilarity, so hold on to your hats.

DSC_2215System Backstory: I managed to get a hold of a Rev. A MacBook Air (Original) in poor (but salvageable) condition a few months ago. It had a damaged hinge, damaged display cable, no hard drive or hard drive ribbon, non-functional on-board sound, no battery and a damaged I/O ribbon. These computers are interesting because their motherboards are quite tiny! Here’s a photo of one. You could put that in just about anything. Plus, it wouldn’t take a large heatsink to convert the cooling system to completely passive! Neat.

Anyway, due to the damage, the computer was extremely cheap. But, it needed some things. A lot of things, actually. Another thing to note, these machines (Rev. A) will only run up to OS X 10.7.5. Additionally, the hard drive is a PATA microdrive. Drives not really known for performance, or long term reliability. Rather than opt to use another PATA microdrive, I sought an upgrade. ZIF-PATA SSDs are expensive for their size. Or, were manufactured by brands with poor quality/poor warranty support. Well, as it turns out, you can get something that performs close to, if not better than those ZIF-PATA devices, with a bit of work.


MacBook Air Rev. A Battery

SanDisk Micro-SATA 64GB SSD

1.8 Micro-SATA to ZIF Adapter

MacBook Air Rev. A Hard Drive Ribbon

MacBook Air Rev. A Display Cable, Hinge and Plastics Set

1.8 ZIF to USB Adapter

USB Sound Card Belkin Ultra-Mini USB Hub

Let’s start with some failure: I thought it would be as simple as popping in a new HD ribbon, connecting the uSATA to ZIF converter, and dropping in my SanDisk SSD… But, for whatever reason the MBA would not detect the uSATA to ZIF converter. But, when I hooked it up to my ZIF to USB converter, it would detect just fine. I found a lot of useful info here, but unfortunately, my tinkering did not pay off.

I tried removing the 5V regulator and components (as the drive in the MBA.A is 3V3, as is my new SSD), and soldering a jumper to force mode select on the adapter. The good news is that the SSD is very short, and fits well (even with the adapter) in the area where the hard drive previously was. I was also able to find some interesting information about the latent USB ports on the MacBook Air motherboard. Which (while unfortunately, only full-speed) could be used for utility devices. Here’s a link to the info on those. My big plan originally, was to solder in the USB sound card onto one of these locations, and wire it into the original headphone jack. But, with the hard drive not working… I had to come up with a new strategy.

I decided the best course of action (Bahahahahahahaha… Best… Right…) would be to cut the USB port out of the I/O panel, wire in a USB hub, and the wire the USB port back into the hub, allowing me to hook up USB high-speed devices internally. Then, wire in the USB sound card, and the SSD via a ZIF-to-USB converter board.

And, that’s what I did. It’s not pretty, and the fitment isn’t wonderful… (There’s not a lot of room in there, not that you needed me to tell you that.), but it works. The benchmarks are respectable given the circumstances. It falls somewhere between UDMA2 and UDMA3. Hardly a speed demon, but it’s very usable. Operates like a normal setup would. The only caveat is that effective disk bandwidth will fluctuate according to activity on USB.

Here’s an Xbench benchmark:

Screen Shot 2014-01-16 at 1.39.31 PM

The Process: I used my Dremel to remove the USB port from the I/O plate, mounted a replacement port in it’s area (which required a bit of Dremel action as well, since that connector is half-length). After splitting the casing off of the USB hub, I removed the 4 USB female connectors, and soldered the hub input onto the MBA root port pads. I used a ribbon cable to connect the new USB port to the USB hub. Then, I removed the micro-SATA connectors from both the ZIF-to-Micro-SATA adapter, and the SSD, and soldered them together. (The connectors add a lot of height to the stack.) I also removed the status LED and USB mini connector from the ZIF to USB adapter, as they also added a lot of height.


I removed the casing from the USB sound card, removed the 3.5mm connectors, and USB male connector. I soldered two ribbons to it, one on the pads for sound output (which were soldered onto their corresponding pads on the MBA 3.5mm jack) , and the other linking the card to the USB hub. I had to cut the 3.5mm jack off of the I/O panel (without damaging it) to disconnect it from the logic board, since it was causing interference, despite not functioning.


Once that was done, I soldered a ribbon from the ZIF to USB adapter onto the hub, and sealed it all up with electrical tape. In the end, the case bulges on that side a bit (but, does not offset the computer…), and I had to remove the aesthetic strut that goes across the bottom panel for some extra room. I sealed all of my solder joints with hotglue once everything was tested and working, and then did my best arrange the components for best fit.




While there isn’t much (re: any) space left, the hard drive ribbon is now unoccupied. I’ve toyed with the idea of trying one of these 8GB Intel PATA SSDs on there, for the OS, and then use the 64GB for extended storage… But, it works great as is. There are some subtle things to watch out for when using USB for your main boot device. Plugging something in could A. Consume too much power, crash your SSD/System, B. Short out the USB hub, crash your SSD/System, C. That port may not charge high current devices, if your SSD is on the same line (because of it’s current draw).


Was it worth it? Well… The value of all the components tallies up like so:

SanDisk Micro-SATA 64GB SSD – 70$

1.8 Micro-SATA to ZIF Adapter – $5

MacBook Air Rev. A Hard Drive Ribbon – $15

1.8 ZIF to USB Adapter – $5

Belkin Ultra-Mini USB Hub – $10

(Note, the auctions I linked are not directly ones I purchased from originally.) Comes to $105. I’m not including the cost of other parts for repairing the other defects in the storage device comparison. Comparatively, OWC has a 60GB drive upgrade (without the need for an HD ribbon) for $130.

That +$25 gets you a 3 year warranty, +40MB/s performance and you can spend the hours of your life you save, watching TV instead. In the end, it’s a wash, but I had fun doing it. The MBA presented me with an interesting challenge.


If you’re one of the Rev. A models with busted sound, give this a try:

Strip one of the $2 USB sound cards down to it’s PCB. Remove the USB connector, and the 3.5mm connectors. Solder a ribbon cable from the USB pads on the sound card, grab 5V and GND from the root port on the I/O panel, and tie D+ and D- to one of the free USB ports illustrated in the linked article above. Solder a ribbon from the 3.5mm output jack pads (on L/R/G) to the 3.5mm jack pads on your I/O panel (check out my photos to see which pads). Snip the headphone port from your I/O panel PCB, and BOOM! Your sound works again (albeit only through headphones).

Project BlackBook: Return Of The Backlight

This project has been hiding on the back-burner for a while, but I finally had some time recently to complete it.

 cat /dev/urandom | hexdump, because The Matrix.
cat /dev/urandom | hexdump, because The Matrix.

A couple months ago, I found myself with a dilemma. As a favor to a friend, I traded them a perfectly working 2009 MacBook Unibody 13 Logic Board, for one with a broken headphone jack (jack snapped off inside, physical damage to the connector) and problems with the keyboard controller. It also had a busted fan.

Replacing the broken components isn’t fun for me, as it stretches the limits of my soldering ability. Surface mount, fine pitch for the keyboard controller, and deep through hole for the headphone jack, make for irritating replacement. Earlier model MBPs had the keyboard controller and trackpad controller built onto a single board (the trackpad itself), and then connected to the logic board via a dedicated USB connector. There were additional pins for the power button, but that was pretty much it. Newer models (Multi-Touch Trackpad 2008+ Models) have the trackpad completely separate, with the keyboard controller positioned on the logic board itself. The keyboard backlight is driven by a WLED driver similar to the LCD backlight in those models, with maximum brightness measured at 18V. The LEDs are wired in series. This design remained constant between the Pre-Unibody and Unibody designs, with the only difference being the Unibody designs contain more LEDs in the chain. Both systems have a separate connector for the KB backlight. Here is a link that describes using the Pre-Unibody trackpad and keyboard as a USB device, which I used to find the pads on my 17″ top case.

I decided the best solution to the logic board problems was to build a Pre-Unibody keyboard (with the controller board) into the body of the Unibody system, and place a USB sound card inside some free space. Measuring out everything was quite fruitful, as I found that both have a recessed area for the keyboard, with the Pre-Unibody keyboard pan being only slightly thicker. The Unibody system is designed with some pretty tight tolerances, so there isn’t too much room for mistake. With that, I began the conversion.

For the rest of the article, I’ll write up U as Unibody, and PU as Pre-Unibody. I’m sure you’re just as sick of reading it, as I am of writing it. (Also, all of these pictures are out of chronological order. Sorry.)

First, I measured out the area of the PU top case to cut out. I left myself a seam of the original palm-level part to work with. I was using a 17″ PU MBP top case as my donor, so I had a lot of spare material in case of a mistake.


Once I cut the pan free, I placed it against the U top case, and measured out where to cut the hole. As I mentioned earlier, the U case has a recessed area in the body for the keyboard, so this was my target area for the new one. The tapered edge of the recess was used as my general guide for the cut.

After this was one, I pulled the keyboard wireframe out of the U top case, and placed in the PU keyboard pan. Using duct tape, I joined the two together by placing strips across the body longways. I then poured clear epoxy into the seam. The duct tape kept the epoxy from running, and gave me a nice smooth seam on the front, with minimal running.


Some curing time later, I sanded the epoxy down to a nice (pretty) smooth finish. I used a test motherboard to see how the fitment was. I found that I needed to grind some of the epoxy down to get the board to fit. After some fancy-footwork with the Dremel, the board fit like a charm.


The thickest area of contiguous free space inside the system is believe it or not, the hard drive bay. At first glance, it seemed to me as though the best area for the extra electronics was going to be the area where the optical drive previously resided. But, it isn’t. There’s much more vertical space where the hard drive is mounted, for a variety of reasons… So, that was where I cut the hole for the relocated USB port and new headphone jack.


I purchased an 8 dollar optical drive slot hard drive mounting bracket, and hacked it to pieces. The HD fit snugly inside the optical drive area, and after some shaving, there was even a little room left over.


Rather than spend any more money on this system, I reused a 2007 MacBook fan as the main fan. Since the fan mount is reversed on these models, I had to mount it upside down. This was a problem for airflow, so I drilled holes in the bottom cover. They were haphazardly drilled, and I’m ashamed at how ridiculous it looks, but, it does the job. I also made the rubber feet much taller in the back using Sugru, which did wonders for my temperatures.


Time for paint! I wish I had the facility to anodize the aluminum of the body, because I’d be all over that. But, I don’t, so paint it is. It’s a shame Apple has yet to release a “Black Edition” of any of the Unibody line, because they’d be pretty.
I thoroughly sanded the main layer, but did not remove all of the aluminum coating on the U top case. The lid I left stock.


I painted both the U top case, and the bottom cover, with two coats of Krylon All-Surface Matte Black spray paint. The coat is reasonably durable, and the Krylon has been resistant the torture of my backpack so far. I would get automotive clearcoat if you really want your paint to last.


Using hotglue, I replaced the right speaker, and mounted the subwoofer to the center support rail. The left speaker needed to be shaved down significantly in order to fit in it’s original position between the logic board and the keyboard pan. I sealed the holes with hot glue (the body of the speaker is hollow for improvement in bass response).

I stripped apart a powered 4 port USB hub that I had (A nicely designed one with a regulator circuit) and cut off the connectors. I soldered a ribbon cable to one of the root ports on the logic board to feed the hub, and then the sub devices were wired onto the hub. I added a USB sound card, a 16GB USB flash drive (case removed), the Trackpad/Keyboard Controller for the PU keyboard, and then wired the last to a female USB port I mounted to the U top case. I mounted the female port using epoxy. You can see in one of the photos, I didn’t properly clamp the port the first time, and it was slanted. I removed it, and had to repoxy it.


I wanted the original KB backlight to work, but I also wanted to try backlighting the trackpad and the ports. I took the LED panel from underneath the original Unibody keyboard, and cut the diffuser down to just slightly larger than the trackpad. I soldered wires onto the ribbon, wired those in series with the PU’s KB backlight LEDs, soldered them to another ribbon, which was then connected to the logic board. (Whew. That was a mouthful.) For the ports, I wired 3.0V fat SMD LEDs in parallel (with an in-line resistor) to the 5V feed of the PU KB controller. The LEDs are secured with hot glue. I used the hub for the 5V source, so that if there is any short of sorts – the hub will protect the root port from being damaged. The root port on the logic board has two beads of hot glue inside the port, so that I cannot plug anything into it.

Testing LED Lit Port Theory


The PU keyboard controller had a limited area where it could be mounted, as the ribbon cable for the PU KB is short. I chose to place it underneath the battery, which is a very tight fit with the trackpad backlight. However, both the PU keyboard controller and backlight panel are very thin, so while it’s tight, there is no adverse pressure on the battery. There is no room on top of the battery for the PU keyboard controller.



Since I cut out the supporting circuit for the power button, there was no way to turn the system on. On every MacBook, there’s a set of pads that can be used to boot the system without the keyboard. For the 2009 Macbook Pro Unibody 13 Inch logic board, these two pads are located next to the trackpad connector. Here is a high res photo. The pads are highlighted in blue. I mounted a large push button on a piece of perforated board underneath the power button, and wired this to those pads. The button is now recessed a bit, due to the difference in height, but I think this ended up being a benefit.


That’s about it. The port LEDs are always on, which does drain a bit more battery than without, but they’re tiny LEDs, so the difference is minimal. Since the TP and KB backlights are wired in series, the fading effects and brightness control still work as they did originally. I wish that the trackpad backlighting effect was more pronounced, but it’s subtly nice. The keyboard is nice to type on. I like the PU style better than the chiclet-style on the U-models for typing, but definitely not for cleaning. The 16GB flash drive is loaded with my Lion ESD Drive, and a seperate partition for my special system images/testing Linux distros, etc. The USB sound card is a $10 job I picked up at a local electronics store. Here‘s a tip for switching your sound output device from the menu bar in OS X, which makes using the USB sound device less cumbersome. I painted over the IR eye, status LED, and battery status LEDs on the case, so… I don’t have those. If you’re more diligent than I, you can pop the little plastic diffusers out before painting. I completely removed the HD ribbon to the logic, to save space in that area. I used way too much tape, and the ribbon cable I chose for the USB was too thick. I think the contrast of the black vs. the silver looks awesome. Overall, I’m very happy with how it looks. It’s an one-of-a-kind eye catcher.

Eventually, I plan on adding a hardware serial port using a USB->TTL converter and a 3.5mm jack. Adding effects to the port LEDs using a microcontroller, and adding more LEDs for the mouth of the optical slot.

There are more photos of the process in the gallery. Now, for the finished shots.

 cat /dev/urandom | hexdump, because The Matrix.
cat /dev/urandom | hexdump, because The Matrix.

DSC_2171  DSC_2191 DSC_2193 DSC_2194 DSC_2197 DSC_2200 DSC_2204 DSC_2207

(TL; DR: I built the keyboard from a Pre-Unibody MacBook Pro into a Unibody MacBook Pro 13. I also added a USB hub, a USB sound card, USB flash drive and relocated an active USB port to the area adjacent to the hard drive bay. The ports and trackpad have also been backlit, and the original keyboard backlight works as well.)