How To Fix Your AirPort Express Base Station

October 6, 2010 Repair Guides, Repair Stories, Site News — Miro

Disclaimer: We debated at length whether this writeup should be a repair guide or a blog entry. Given the very destructive nature of the repair, as well as the iffy probability of your device working afterwards, we decided the writeup was to remain a “hey, look what you could possibly do” blog post, rather than a specific set of instructions on how to fix your AirPort Express Base Station. If you still attempt to do this at home, consider yourself gently warned.

One day I came into our office and there were three AirPort Express Base Stations sitting on my desk, all labeled “Non-working.” I couldn’t believe it, so I plugged them in. Alas, they did not work, just like the Post-its instructed.

Word spread around the office regarding my new-found treasure, and one of our mechanically-inclined enginerds, Andrew, took it upon himself to fix a unit or two. After all, our site is called iFixit, not iThrowItAway.

He came across problem #1 very soon: merely opening the plastic suckers. Both of us tried all sorts of tools to neatly open them, to no avail. We kept increasing our force, and finally succeeded with two different methods. Andrew used a heat gun and Dextered the case using Exacto knives and flat-head screwdrivers, while I went the light-saber route and melted through the case seam with a soldering iron*. The method that Apple engineers used to adhere the two halves of the case produced such a strong bond that the plastic surrounding the case cracked, not the seam itself (in Andrew’s attempt, at least).

And this is why we’re not making it a repair guide:

Kind of like opening a clam, but much harder.

Inside were two separate PCBs. On the left was the power supply for the base station, on the right the AirPort Express card and sound board. Note the jagged edges around the case perimeter, evidence of the destruction needed to open it.

Two halves make a whole.

The power supply, which we suspected was the cause of our troubles.

Andrew handled the repair from this point. He immediately focused on the power supply, as none of the AirPorts were powering on. After a bit of unscrewing and unwrapping, he quickly realized the problem: both units contained burnt components in the same exact part of the power supply, rendering them useless.

Our problem is indicated by red markup.

Turns out the board was almost completely burned through near an inductor on the top side of the board. On other side there were two SMT resistors that also bit the bullet. It was not a pretty sight.

Resistors, well done.

Inductor, which we believe caused all the shenanigans in the first place.

As Andrew found out, fixing the power board proved to be a futile exercise. The inductor had continuity between its contact points, and it was assumed to be somewhat functional. He soldered new resistors on the other side of the board, but no amount of manipulation would fix the board. So he tossed it aside and focused on providing an alternate source of power to the AirPort card inside the unit.

Some astute readers may have noticed the output power ratings on the Samsung sticker Andrew removed from the power supply. This crucial piece of information allowed him to analyze the problem further. Apple usually doesn’t give out carrots like these, so they must have thought that nobody would be crazy enough to open up an AirPort Express Base Station. Silly Apple.

Written on the power supply in all caps: OUTPUT: “+5V @ 0.7A,” and “+3.3V @ 1.21A” — score!

Since there was one cable connecting the two boards together, Andrew had little trouble figuring out where the power was coming in. The tricky part was to figure out which wire provided the 3.3V and which the 5V input. Kind of like “do I cut the blue wire or the red wire” on a bomb, but with less explosive potential results.

The second problem of the day was finding a ~3V power supply. We had a generic 5V, 1A phone charger laying around, but nothing near 3V. So Andrew did what any other self-respecting enginerd would do: solder two AA batteries together. A short while later, he had mockup #1 emitting an orange light.

If you look really hard, you can see the two orange LEDs near the top-right of the PCB.

Great news! Except not really. Even though the AirPort Express Base Station powered on, it would not retain custom settings once we tried to set it up properly. The second unit exhibited the same exact problem. No amount of tinkering by either Andrew or yours truly would alleviate the problem, so we abandoned the project for the remainder of the day.

That night I got a text message from my persistent co-worker, who took the project home to work on it in his own time. It read: “I guessed wrong. Swapped the wires and it works!!!” We had discussed swapping wires earlier in the day, but figured that the unit wouldn’t power on at all, and that something else was the problem. Sometimes we shouldn’t overthink things and just do them.

So here is the correct wiring setup:

  • Black wires: ground. All three should be connected to the two ground wires from the power supplies.
  • Red wire (middle): 5V, 0.7A power input.
  • Orange wires (two on the right): 3.3V, 1.21A power input.
  • If you have trouble discerning the wires in the image below, check it out in full-res.

    The AirPort board is the only one worth saving, since it most likely works fine.

    Andrew wanted to do things proper the second time around — no AA battery funny business anymore — so he went to Radio Shack and acquired a 3V/4.5V/6V/7.5V/9V/12V switchable power supply. The final setup, which I’m listening to while typing this, looks like this:

    Not pretty, but it works.

    R-Shack wanted a steep $20 dollars for that fancy power supply, but convenience is king. For our other soon-to-be-fixed units, we found some great cheapo power supplies on Ebay that should work just fine. We won’t know until a couple of weeks from now, so we’ll keep on rocking with the R-Shack power source for now.

    Final power supplies that we used for our gizmo was an R-Shack 3V, 1A and a 5V, 1A power supply. We also put the AirPort card back into its half of the plastic shell. This is how it looks like when in use:

    It keeps quite cool.

    So far our AirPort “Bass” Station has been working consistently for four days with no problems. Still, we unplug it at the end of the day, just in case it decides to light on fire one of these days…

    * By the way, the soldering iron is the way to go when opening these things, as long as you do it in a well-ventilated area and don’t mind potentially destroying a soldering iron tip. It’s also relatively safer, given that the Exacto blade can stab you in the heart really bad.

    21 Comments

    1. I’ve taken apart a number of computer power supplies, and they all use Red for 5V; Orange for 3.3V, Yellow for 12V, and Black for ground.

      As a side note, an old computer power supply makes a great power supply for an electronics bench, because it puts out most of the common voltages and has plenty of power.

      Comment by trainman — October 6, 2010 @ 4:47 pm

    2. damn- nice job guys, this is the kinda cool hackery and ingenious repair I love to see.
      Btw- any tips on the “lightsaber method”? I’m trying to get into the brick in a magsafe charger that broke- metal spudgers pried it a bit at best, but no luck, I think i’ll try your method now.

      Comment by rab777hp — October 6, 2010 @ 4:52 pm

    3. Here are some tips for the “light saber method”:

      1. Ventilation. Do your “light sabering” near a window or door, or outside. The fumes could be very toxic, and I won’t be liable if you get cancer.

      2. Let the soldering iron get real hot — give it 5-10 minutes to heat up beforehand, depending on which one you have. I used a 35 Watt “expendable” soldering iron from the Dollar Store, so it doesn’t have to be anything fancy.

      3. Work slowly around the perimeter of the device. You’ll have to judge for yourself how deep to insert the soldering iron tip. I’d say to err on the side of caution and work through a section once or twice, going in deeper the second time. That way you won’t accidentally start desoldering components inside the device while trying to get it open.

      Hope that helps!

      Comment by miro — October 6, 2010 @ 5:02 pm

    4. thanks that sounds good- whenever i melt plastic with a soldering iron i usually wear a mask as a precaution.

      Comment by rab777hp — October 6, 2010 @ 5:13 pm

    5. So after you melt away the plastic seam how did you pry it apart? I’ve gotten there but there seems to be now way of prying it apart.

      Comment by rab777hp — October 6, 2010 @ 6:16 pm

    6. Ah- metal spudgers got it, a little tricky and it bent them a tad, but it worked! Now for a look inside…

      Comment by rab777hp — October 6, 2010 @ 6:27 pm

    7. It takes a bit of force to pry the base station apart, even after melting the plastic seam. You will hear a lot of scary cracking noises, then it will suddenly give way and you’ll have a half in each hand.

      Comment by miro — October 6, 2010 @ 6:34 pm

    8. Yeah that’s pretty much what happened- it’s actually real interesting inside this, you guys ever taken a look inside one of these?

      Comment by rab777hp — October 6, 2010 @ 6:38 pm

    9. It would appear it’s manufactured by [http://www.delta.com.tw|Delta Electronics]

      Comment by rab777hp — October 6, 2010 @ 6:49 pm

    10. Really!? The day I walk down to my garage and find my AirPort Express has stopped working you have posted a blog entry about it? And it comes up in Google when I’m searching for others with this problem? Nice job, your photos are much better than my iPhone photos at my dark workbench. My power supply looks just about like yours, burned all the way through, maybe a little more well done on the top edge though.

      Comment by J.P. — October 7, 2010 @ 2:03 am

    11. […] took a few photos with my phone, but did some searching and found iFixIt posted a blog entry today, with better pictures than I am going to take a 1:00 in the morning. No […]

      Pingback by An Air Port Tale — October 7, 2010 @ 2:12 am

    12. Please read before trying to repair yourself:
      My 2-year old Airport Express (APE) died last month. Apple gave me a new one!

      I bought the Applecare Protection Plan (ACPP) for my laptop a few years earlier – still have a few couple months to go before expiration.

      I did NOT buy the ACPP for my APE.

      I found out… If you have ACPP, they WILL replace your APE (AP express and AP extreme) for FREE.
      What a pleasant surprise!!! Another reason I buy their products.

      Try ACPP (if you have one) before opening it up to fix yourself.

      Comment by Apple Replaced Mine — October 7, 2010 @ 12:54 pm

    13. Looking at the damage and taking guesses at the surrounding components, I’m thinking that one or both of those larger filter caps has failed shorted, dumping a lot of leakage current through the SMT resistors on the underside of the board.

      Can’t say with 100% certainty because the photos aren’t clear enough to see exactly what the connections are but it would make sense. The inductor just happens to be sitting on top of where the board got scorched from the overheated resistors.

      I also see some gunk around gasket seal on the positive lead on the left-hand-side capacitor that may be a sign of that being shorted (i.e. the electrolyte was beginning to leak out.) Again, can’t really tell, maybe those looked like that brand new.

      But in general when PSUs blow up, caps are your first place to look. Those claim to be rated 105 degC but they’re also no-name brand and stuffed someplace where they could become very hot.

      This may actually be repairable assuming something upstream hasn’t fried as well.

      Comment by necoro — October 8, 2010 @ 9:37 am

    14. Great comment, Necoro. I updated the three “power supply supply damage” images above with links to the full-resolution shots. You can click on any of the three to see the mayhem in all its gory detail.

      Enjoy!

      Comment by miro — October 8, 2010 @ 10:43 am

    15. […] Fuente: iFixit […]

      Pingback by MacKinando » Curiosidades » iFixit, “reparando” una estación base Airport Express — October 8, 2010 @ 9:21 pm

    16. […] Fuente: iFixit […]

      Pingback by UR-VE.COM » Blog Archive » iFixit, “reparando” una estación base Airport Express — October 9, 2010 @ 12:27 pm

    17. Excellent job and excellent pics!

      Comment by Bart — October 15, 2010 @ 12:45 pm

    18. Here are suggestions on (1) easier ways to open up the case (2) using a single 5V supply with a 3.3V regulator.

      http://echoone.com/airport-express/

      Comment by CityZen — October 17, 2010 @ 5:42 pm

    19. Just FYI, I recently opened one of my fully functional AE base stations, just for the ‘fun’ of it… It turns out mine must be a more recent model… I still had to destroy the case to open it up, but they seem to have changed the voltage requirements. They no longer color code the wires, they are all black now, and a bit thinner gauge wire as well. They’ve also eliminated the need for a 5v power source. There are still 6 wires, but 3 of them are ground and the other 3 are all 3.3V…

      Comment by Sean Knudsen — January 30, 2011 @ 2:30 am

    20. I took my AE apart with a Dremmel. Very quick. I connected a 5V PSU in a separate box, & used the echoone.com voltage regulator/capacitor solution to get 3.3 V. The AE is now piggy-backed onto a similar sized plastic box containing the switch mode PSU/voltage regulator. The whole thing is held together with glue from hot melt glue gun. In hindsight, I should have re-housed the entire hack in a single, larger box. I will try to make the original AE box look nicer by sealing with white silicone when I have time….

      Comment by The Judge — February 11, 2011 @ 2:34 pm

    21. I would also use a Dremel with small rotary saw (carefully) – I have done this before to repair MacBook power supplies with frayed wire problems.. Regarding the Airport Express photos, specifically the one captioned “Two halves make a whole” in extreme bottom left of right hand ‘half’ is that a lucent socket that could be used to run an external wi fi signal receiving boosting antenna out of? just curious ;-)

      Comment by Richard — February 14, 2011 @ 7:01 pm


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