September 20th, 2009

Replacing the keypad on a Korg Microkorg

 

 I know of more than one Microkorg that has needed a new keyboard installed, just in my own little town.  Considering that this marvelous little unit  is one of the most successful synthesizers ever marketed, it seems likely that this simple repair job would interest a few folks.  I'm not suggesting that the keypad is a weakness in the Korg, just that these popular, portable machines get much more and varied use than the average synthesizer.

The Microkorg is too good to be done when the keyboard fails!

The first piece of good news is that replacement keyboards are inexpensive and as of this writing, still being supplied by Korg.  I paid about $40.00 Canadian through my local authorised Korg dealer, Tony's Music Box in Fredericton, N.B. 

The second piece of good news is that it is an easy fix.  The keyboard is accessible without any major surgery, is easily removed and the new one slipped into place almost by itself.  No soldering or other special skill is required.  There are no seated springs or other surprises waiting.

Here is the unit that needs the work.  Bought cheap off Ebay, it has been heavily used.  There are lots of small scratches and nicks in the paint, but everything works except the upper octave of the keyboard.  You can see that the keys sit unevenly.  The rresponse gets increasingly mushy as I play up the range, until there is none.  The aluminum bed of the keypad has actually been distorted. 




















Access to the keypad is through the back panel, so we are going to be working on the unit upside down.  To avoid putting pressure on the knobs and pots, I am holding the front clear of the worksurface by propping the Microkorg up on two books.  Anything will do, but make sure the unit is stable and won't slip around while you work.


















We don't want any current at all running around inside the box while it is open, so remove the batteries just to be on the safe side.




The replacement unit consists of the key mechanism installed onto a controller daughter board. 








Several of the panel screws are deeply seated at the bottom of a long access tunnel.  They are philips head.  If you happen to have a screwdriver with a shaft near the same diameter, it is very simple to drop in in, rotate it until the heads engage.  The access tunnel keeps everything lined up.  If not, there might be
some fumbling involved.

















I suggest you leave these screws in their tunnels and hold them in with a piece of tape until ready to re-install the panel.  You will know where they are, and the same screws will go back into the plastic threads they came out of.


When all the screws are loosened or removed, the back will be free to move up and flip away from you, and will remail attached  to the motherboard by three bundles of jumper cables.  The leads are long enough to work comfortably here, another reason to admire the design of the Microkorg.





You are now looking at the bottom of the old daughterboard inside your Korg.  You will see it is held in by several small screws.  Take 'em out and put them in a very safe place.  These little black screws have a way of falling to the floor never to be seeen again!









Okay, now you are ready to detach the three bundles if wires.  Don't worry, the plugs are shaped so they can only be put back together the right way.  Pry them out, gently .  This takes a little bit of pressure since they are desgned to stay put when the synth is being a synth.





 

One more step before removing the faulty component.  You will see that the daughterboard is also attached to the Microkorg guts by two wires, one on each end.  Fortunately for most if us, the are attached by a screw and eye arrangement.  They aren't soldered. (Whew!!)

I don't have any idea what they do, but I know for sure that  I want to attach them to the new unit exactly as they are attached to the old one!!





The keypad assembly is now completely loose.  I is removed by gentley rocking it forward from the back, and lifting up asd seen below.




The new keyboard is installed by exactly reversing the procedure.  No tricks to it at all.
 Here is the new keypad installed.  Note how much more even and smooth the keys are.


Close up your back panel.  Thurn the machine back over, and enjoy your refurbished MicroKorg!!