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.
System 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.
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:
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:
(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).