XBase09 switch cleanup

Friend of mine donated me a defunct XBase09 describing its fault as “sequencer broken but sounds can be tweaked and triggered using MIDI”. Sure thing, I’m up for a analog kick / snaredrum sound module, especially after my 9090 project failed way too close to the finishing line.

So, I get the device in my hands and start looking for a fault. Power up, lights activate and the unit seems as if the CPU is perfectly fine. It’s just not responding to any keypresses.. sound triggering switches work fine though. I move on to check how the keyboard is wired up and also measure a particular switch for conductivity.. Bingo! Switches not making proper contact.

I then spent a good few days digging the net for replacement parts, only to find roughly about zero shops. Sure, the pin spacing is standard and there are tons of halfway-there replacements, but getting a illuminated version of the switch..  Oh crap, defaulting to switch cleanup then.

The switch has four tabs holding the actuator / LED top cover in place, these are the black circular ones visible in the following picture. They’re slightly melted from the top to clamp down the cover, thus prying needs to be done carefully as not to break the corners. I used a small pin, lifting gently from both sides little at a time.

Opening a switch using a pin..

Finally, off the cover comes! Looking at the contact plate and the base part, it’s no wonder the switch is not making contact :). Not that it was anything a q-tip soaked in isopropylene couldn’t clean..

The switch actuator cover, contact plate and the switch base.

Good thing is that despite the cover of the switch is not “factory sealed” anymore after this cleanup, it still holds in place pretty ok without melting the tabs again. Small dabs of cyanoacrylate glue could also be used to fasten the cover back in place: I assume that the next time a unit serviced in this manner needs switch repairs, they need to be replaced altogether..

If you happen to know a electronics shop in the net that delivers worldwide mail orders AND stocks these switches, I wouldn’t mind about being clued in on it.. And no, I’m not placing a factory order just to get a handful of these switches ;).

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12 responses to “XBase09 switch cleanup”

  1. Nico says :

    Even if this artikle is a little bit older: I hope that you read this comment and can help me.

    I just bought a secondhand XBase and I am struggling with the same problem: The buttons especially the ones of the step-sequencer are not very responsive. I found out that Sparkfun is selling these buttons (https://www.sparkfun.com/products/10442) and they have them in stock (even in different colors!) It might be a little late but perhaps it helps you.

    But I have another question: Do you remember how exactly you took the XBase apart? I loosened all the housings-screws and removed the backpanel. After that I removed the screws which held the main PCB in place. The main problem right now is how to remove the main PCB? I noticed that the two PCB in the housing are held together by standoffs. But I was not able to remove the PCB. Do you remember any tricks?

    • Arto says :

      Hey thanks for the switch tip, good one!

      If I recall this correctly, you need to first remove the six screws in the bottom and the top screw on both sides. After this the bottom plate comes of with the sides attached. Main PCB is attached with nuts on both the PCB and on output jacks. Remove these and you should be able to lift the board out.

      • Nico says :

        Thanks for the hint. I guess I have overseen one of the nuts that holds the PCB. When I first tried to disassemble the device I was not able to lift the PCB from the spacers. I’ll give it another try on the weekend when the buttons have arrived. Shipping from the USA to germany takes time… ;-)

        • Wl says :

          Hi, did you manage to switch buttons on your xbase09 with the sparkfun ones? How easy was it, and do they work like the original ones?

        • Arto says :

          Hi, did you manage to switch buttons on your xbase09 with the sparkfun ones?

          Nope didn’t order a set, was supposed to look up some alternates suppliers but the task got buried with other stuff and forgotten.. Maybe this is my reminder :)

        • Nico says :

          Hallo WI.

          Ich alle Tasten auf meinem XBase ersetzt vor ein paar Monaten. Es dauerte etwa einen Abend der Arbeit. Die meiste Zeit war zum Entlöten die alten Tasten erforderlich. Die neue von Sparkfun haben genau die gleiche Größe und Pin-out. Der einzige Unterschied ist, dass sie ein bisschen mehr Kraft zum Drücken benötigen. Aber als meine XBase scheint zu sein,> 10 Jahre alt ich denke, dass dieser Unterschied kommt von der verschleiß aus den alten Tasten nach so vielen Jahren. ;-)

          Versand diese Tasten, von den USA nach Deutschland nahm ca. 6 Wochen, aber es war das Warten wert.

        • Benjamin Thomas says :

          Hi, Nico, Arto – please can you advise, how did you get the PCB out? It seems that the PCB is trapped by the case at the front, and that if only the on/off switch could be removed easily that the PCB would come out. I need to take the PCB out because someone has trapped a wire in the wrong place and I need to reroute it, as the ports don’t align properly any more

        • Arto says :

          Hi Benjamin. Sorry but I don’t have the XBase anymore, and can’t remember the mech structure from top of my head. Did you try taking it apart somewhat like I wrote above?

        • mathsmechanicgmailcom says :

          Thanks Arto, yes I tried as you described but the board still seems trapped by the case. Will try again soon. Thanks for replying!!
          Ben

  2. Nico says :

    Hi WI.

    I replaced all the buttons on my XBase a few months ago. It took me about one evening of work. Most time was necessary for desoldering the old buttons. The new ones from Sparkfun have exactly the same size and pin-out. The only difference is that they need a little bit more force for pressing. But as my XBase seems to be > 10 years old I think that this difference comes from the wear-out of the old buttons after so many years. ;-)

    Shipping these buttons from the USA to germany took ~ 6 weeks but it was worth waiting.

  3. Walt says :

    I brought one a year or so ago, major issues with the buttons working. However, I discovered you can just pop the red caps off with a pin and use some Deoxit to spray between down the gaps.. No need to remove buttons, or open the case up at all! Did this to mine and works 100%.

    • Arto says :

      I discovered you can just pop the red caps off with a pin and use some Deoxit to spray between down the gaps.. No need to remove buttons, or open the case up at all! Did this to mine and works 100%.

      Thanks for the tip! I eventually ended up replacing the switches on mine with new ones, brighter LEDs and all :)

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