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I returned home from a recent trip to a tragically non-functioning espresso machine. When I powered it on, I could hear a relay clicking, probably trying and failing to turn the pump motor on. On a commercial-grade machine like mine, a Fiorenzato Bricoletta E-61 design, this often means your microcontroller box, or brain, is kaput. This being an Italian-made part with no benefit of consumer-level economies of scale, the replacement is about $200. Yikes.

I put my multimeter on the pump motor wires and could see it spiking at about 28V, but never supplying sustained current. This helped confirm that something was ill in the machine’s brain, but I hoped it might be a single component, rather than the whole unit.

I put this video up on my favorite coffee forum, Home-Barista, to see if anyone could help me diagnose it:

This lead to a correspondence with James “Pat” Boyt, who said it looked like a “dried up” power capacitor to him. I pulled the brain, tested the big brown capacitor in the above photo, and sure enough, it was dead. I desoldered it, replaced it with a new 330uF 35V capacitor rated to 106 C, and reconnected the brain. I plugged in the machine, flipped the power switch, and it powered right up. Hurray! That’s a 19 cent part, instead of $200.


There’s nothing quite like the internet for getting expert advice on a problem. I’m grateful for Pat’s guidance in bringing my machine back to life.

John Edgar Park

John Edgar Park

John Edgar Park likes to make things and tell people about it. He works in CG animation at DisneyToon Studios and writes for Make, Boing Boing, and other places online and in print. You can find him at jpixl.net and twitter @johnedgarpark — if you like that sort of thing.


  • http://pulse.yahoo.com/_2ZIJ6TNUVN46CYJODGKMRLIXZU Dave

    Is this yet another incident of the dreaded “bulging capacitor syndrome”?

    • http://www.google.com/profiles/jedgarpark John Edgar Park

      Dave, it wasn’t bulging, but it was definitely dreaded.

    • http://www.facebook.com/people/Russ-Gephart/1102943244 Russ Gephart

      Congratulations!

      Based on my experience, electrolytic caps are usually the culprit. Especially on a solid-state board that lives in a warm environment. It’s where I always look first.

  • Anonymous

    It’s truly amazing what a bad cap can do, glad to see you solved the problem, rather than creating a landfill problem. Seriously, big kudos for that and the example you’ve set.

    This reminds me of the famous bad capacitor plague of the mid 2000’s, thousands of really expensive (and toxic) machines ended up as landfill because of shoddy corporate espionage. The chemical formula was improperly copied, leading to bad capacitors that failed in about a year.

    Modern supply chain quality control has become so very critical in general, but you don’t hear much about it.

  • Anonymous

    It’s truly amazing what a bad cap can do, glad to see you solved the problem, rather than creating a landfill problem. Seriously, big kudos for that and the example you’ve set.

    This reminds me of the famous bad capacitor plague of the mid 2000’s, thousands of really expensive (and toxic) machines ended up as landfill because of shoddy corporate espionage. The chemical formula was improperly copied, leading to bad capacitors that failed in about a year.

    Modern supply chain quality control has become so very critical in general, but you don’t hear much about it.

  • http://pulse.yahoo.com/_NGG3X3YQQVZLFJ5ANY3VIKN7HM James

    This is why I love hacking

  • http://pulse.yahoo.com/_NGG3X3YQQVZLFJ5ANY3VIKN7HM James

    This is why I love hacking

  • http://twitter.com/fg_tech Fairy God-Tech

    Way to go on the diagnosis! Not to mention avoiding that $200 price tag. Out of curiosity, how many people-hours did it take from “something’s wrong” to finding the dead capacitor? I’m wondering what the “labor cost” was on this.

    • http://www.google.com/profiles/jedgarpark John Edgar Park

      Great question. I think I spent an hour or two trying to isolate the problem, 1/2 hour shoot a video and posting on home-barista, corresponding, finally about 15 minutes desoldering the bad cap and soldering in the new one, and reconnecting things. If I’d relented and bought the $200 Gicar unit, it would have been after the first two stages (poking around, video), so the post-capacitor-revelation labor cost would have been fro 15 minutes.

  • http://twitter.com/fg_tech Fairy God-Tech

    Way to go on the diagnosis! Not to mention avoiding that $200 price tag. Out of curiosity, how many people-hours did it take from “something’s wrong” to finding the dead capacitor? I’m wondering what the “labor cost” was on this.

  • http://twitter.com/fg_tech Fairy God-Tech

    Way to go on the diagnosis! Not to mention avoiding that $200 price tag. Out of curiosity, how many people-hours did it take from “something’s wrong” to finding the dead capacitor? I’m wondering what the “labor cost” was on this.

  • http://twitter.com/fg_tech Fairy God-Tech

    Way to go on the diagnosis! Not to mention avoiding that $200 price tag. Out of curiosity, how many people-hours did it take from “something’s wrong” to finding the dead capacitor? I’m wondering what the “labor cost” was on this.

  • http://twitter.com/fg_tech Fairy God-Tech

    Way to go on the diagnosis! Not to mention avoiding that $200 price tag. Out of curiosity, how many people-hours did it take from “something’s wrong” to finding the dead capacitor? I’m wondering what the “labor cost” was on this.

  • http://twitter.com/fg_tech Fairy God-Tech

    Way to go on the diagnosis! Not to mention avoiding that $200 price tag. Out of curiosity, how many people-hours did it take from “something’s wrong” to finding the dead capacitor? I’m wondering what the “labor cost” was on this.

  • Anonymous

    Good job! Sometimes, the most satisfying repairs are the ones you do on the things you rely on the most. Glad to know that you could isolate and replace the broken part yourself. I hate it when products are difficult to repair and you have to throw it out.

  • http://www.facebook.com/profile.php?id=1046265143 Ming Wu

    How did you and Mr. Boyt figure out that it was the capacitor at fault?

    • http://www.google.com/profiles/jedgarpark John Edgar Park

      I have to credit Pat with that — I think he’s learned it by experience. The motor was trying to turn, in tiny little pulses, and when I put a meter on it I could see the brief spikes in current. Since the motor turned freely when I put a screwdriver in the rotor slot and turned, it wasn’t (thankfully) a damaged motor or pump. I’m conjecturing here, but I suspect all this lead Pat to think that the microcontroller was telling the system to turn the pump, but some discreet component was failing its job.There are few enough of them on the boards that you could test them one by one, but Pat’s guess pointed me toward the failed capacitor on the first try. I’ll ask him for a more scientific answer, if he has one.

    • http://www.google.com/profiles/jedgarpark John Edgar Park

      I have to credit Pat with that — I think he’s learned it by experience. The motor was trying to turn, in tiny little pulses, and when I put a meter on it I could see the brief spikes in current. Since the motor turned freely when I put a screwdriver in the rotor slot and turned, it wasn’t (thankfully) a damaged motor or pump. I’m conjecturing here, but I suspect all this lead Pat to think that the microcontroller was telling the system to turn the pump, but some discreet component was failing its job.There are few enough of them on the boards that you could test them one by one, but Pat’s guess pointed me toward the failed capacitor on the first try. I’ll ask him for a more scientific answer, if he has one.

  • http://www.facebook.com/profile.php?id=1046265143 Ming Wu

    How did you and Mr. Boyt figure out that it was the capacitor at fault?

  • http://www.kentkb.com kentkb

    Far out dude.
    I just spent $280 for a new “brain” to fix my old Isomac Millenium.
    Just think of the amount of green coffee beans that would buy….

    • http://www.google.com/profiles/jedgarpark John Edgar Park

      Maybe you can try to repair the old board and sell it to someone in need, Kent. Then buy some beans!

    • http://www.google.com/profiles/jedgarpark John Edgar Park

      Maybe you can try to repair the old board and sell it to someone in need, Kent. Then buy some beans!

    • http://www.google.com/profiles/jedgarpark John Edgar Park

      Maybe you can try to repair the old board and sell it to someone in need, Kent. Then buy some beans!

  • http://www.kentkb.com kentkb

    Far out dude.
    I just spent $280 for a new “brain” to fix my old Isomac Millenium.
    Just think of the amount of green coffee beans that would buy….

  • http://www.kentkb.com kentkb

    Far out dude.
    I just spent $280 for a new “brain” to fix my old Isomac Millenium.
    Just think of the amount of green coffee beans that would buy….

  • Anonymous

    link to thread would be healpful

  • Roula I.

    Your post is awesome!
    I turned on my ECM Giotto today and heard the exact same clicking noise you mentioned. I did a couple of google searches and came across your posting. I knew immediately that what you described was my problem, then I heard it in your video.
    Based on your diagnosis of a dead capacitor we got the machine up and running in no time, and it cost us only 59cents! Thank you, thank you, thank you!

  • http://www.cloob-fa.ir/ShellaLac Van

    I love it when individuals get together and share
    ideas. Great website, keep it up!

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