Instructables

Bypass Your Broken Airport Express PSU with an USB Power Source

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Picture of Bypass Your Broken Airport Express PSU with an USB Power Source
Ever have an Airport Express (AE) that will not power up anymore? Most likely it is from a broken power supply unit.  The cause is usually from a bad 3.3v regulator and/or bad capacitors.  This guide will show you how to bypass Airport Express PSU and power it with USB power.  This will great if you want to use an 5v USB A/C adapter, power it off your computer, or use any other USB power source.

Here is a list of suggested tools and materials you might need:
Airport Express
Hand Saw
Multimeter
Soldering Iron, Solder
USB cable
USB Compact Flash card reader, $2 online (slightly smaller than the AE so it fits inside)
3 wires (2-3inch in length), one for ground, one for 5v and one for 3.3v.


Update: I changed the blue tape to white tape on the reassembly of the housing.
 
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Step 1: How to Open the Airport Express Case

Use the hand saw and cut along the case seam of the Airport Express.  The seam is where the two pieces of the case is joined together. The depth you need to saw is 1/8 of an inch. You should stop right when the plastic breaks through and you can see the insides.  Go slowly as you do not want to damage anything inside.

Step 3: Test the CF Memory Card Reader

Picture of Test the CF Memory Card Reader
Use your multimeter and find the locations of the ground, 5v and 3.3v on your CF Memory Card reader.  I am using the CF memory card reader for two reasons. One, it provides me with an existing USB port. And, two, a CF card reader provides a 3.3v output.  AE runs on both 5v and 3.3v.  You can create your own 3.3v stepdown if you want. 

You can use your multimeter and test your power supply too. A word of warning, there is a risk of electric shock if you do decide to tinker with your broken AE power supply.


GrittyD13 days ago

Thanks for the research and writeup - Since I have no card reader with 3.3v output I have just added two a LM1117 IC to a 5V wall mount adapter to get both voltages.

However: the airport express wants a lot of power. I think at least a 1A 5V adapter is a must (but everyone with a RapsberryPi around probably has one of those)

twalda1 year ago
What CF Card Reader did you use? and for some reason all 6 wires of mine are black.
kyeology twalda9 months ago
You ever figure out what the black wires voltage output where? I'm in the same boat.

Same for me : all 6 wires are black, have you sorted it out ?

wmmt31 year ago
Hey man, regarding the power cable from the AE. I had a speed bump! I think mine is most prolly second gen or just from a different batch. The power cable is all black. :\ Help?
Idaho542 years ago
Hi,
I just made the fix, and it seems that I need some help... I have locate the ground, 5v and 3.3v on my CF Memory Card reader, wire them, plug the power cable back into the AE and Power up the USB CF memory card reader. Eureka; the AE light up in green! But that's all... My AE is not visible on the wifi network... :( So i recheck my wires with my multimeter, and then i see the 3.3v was no longer on 3.3v but on 1v! So I unsolder this wire, check an another time the 1v on the CF Memory Card reader and mesure 3.3v... In conclusion the 3.3V drop to 1v when i wire it on my AE. May this explain the fact that the AE does not work? How to explain and remedy the voltage drop? I really need to fix my AE... Thank you in advance for your help.
imjasonc (author)  Idaho542 years ago
try this first: when your AE lights up, hold the reset button to force the AE to reboot until your airport utility on your computer detects it. if your AE works, then you should be able to configure it.


the voltage might drop since theres a load now. good luck.
I have tried it, but the AE don't reboot. The led stay green, and nothing happen. :(
imjasonc (author)  Idaho542 years ago
sorry cant help you there, could possibly be that something else is wrong with the AE or that theres other power issues. my guide is only to replace the power supply with usb power. you might need to experiment and test the AE.
Idaho542 years ago
Nice repair! But my problem is that i'm a newbee in electronic, and i'm not sure to correctly locate the ground, 5v and 3.3v on my CF Memory Card reader. In fact, i have found the same Memory Card reader as you; can you post high resolution pictures of your soldering to be sure i'm not doing mistakes? Tx!
imjasonc (author)  Idaho542 years ago
you could probably google how to use a multimeter. if you need help on soldering or other tools in this guide, you can probably find videos on youtube. good luck.
nice fix....have a fix for a burned-out processor? I bought one of these and promptly murdered it. the modems didn't last either....
rrepass jr.3 years ago
boy I hope I can find the AE that died some time ago... I've been a sad camper over that loss! Hopefully not for long!

GREAT mod, thanks imjasonc :)
Kapower3 years ago
Actually, fiddy one cent or sixty cent
just a thought, but due to the higher draw than that cf card reader is used to using, why not just try to add it to your psu inside a desktop. i know that my 5v and 3.3v rails will support a hell of alot more than the amperage needed. though a step down circuit and a 5v psu like a usb car charger and a sla or other 12v source could make a nifty little semi portable wifi spot. that could be used for the myfi cards they sell these days because i know how small a radius those can have. the airport can then just amplify the myfi card, say, from in a car! the ideas are endless. you could even have a netbook with a itunes library stream music to a car audio system simultaniously. i might just do the mod with or without the dead power supply! =]
imjasonc (author)  ForgetfullDeity3 years ago
youre right, you can use any source that outputs 5v and 3.3v such as a computer psu. heck, you can build a battery back if you wanted to. have fun modding.
jptrsn3 years ago
Very cool! I have two AEs at home. Both still work, but when one finally quits, I'll hook it up to some kind of power regulator with 5V and 3.3V (maybe not one of my two USB ports!)
imjasonc (author)  jptrsn3 years ago
sounds good. there are different ways of getting a new power source. you could always find a 5v ac adapter and just create a 3.3v step down regulator. have fun!
junits153 years ago
what is an airport express?
Kind of like an access point, can be used for extending a home wifi network or using it in a home wifi connection to share internet, files, itunes...etc.


More info here:
http://www.apple.com/airportexpress/
imjasonc (author)  Valas Hune3 years ago
I thought it was the shuttle to the Airport... Jk. =)