A fix for Korg nanoPAD PADs not working

I’d bought this over a year ago and never really got it working and put it aside as I had got a nanoKEY and a nanoPAD (Black) and just used the nanoKEY.

Recently I found this again in the cupboard and thought that I really had to get to the bottom of why it did not go (I was using Ubuntu so blamed that to start with without following it up).

I plugged it into my Ubuntu machine (10.10) and used the MIDI monitor in Qmidiroute and only saw the X-Y events – this does pitch modulation, plus the system events for the scene button but not a single event from the 12 PADs.

I also plugged it into Windows and used a MIDI monitor and also had no MIDI events for the PADs. This really did seem to be a hardware problem and nothing to do with Ubuntu. I really should have done this test before the warranty expired but this meant I could open it up without any guilt.

Under the bottom of the case under the tiny rubber feet are 6 screws. Remove these. You will see a metal plate which is the support for the 12 PADs plus a copper shield, 1 large flexible ribbon cable for the PADs and underneath that 1 small flexible ribbon cable for the X-Y control. These plug into a PCB.

With it plugged into the USB and with the MIDI monitor program going I checked I had X-Y events and no PAD events. I then popped off the clip to the large cable that goes to the PADs and as I removed it then I got events. This suggested some alignment issue or short i.e. the chip is OK.

I unscrewed the PADs metal plate – I removed the copper shield cable (it is glued at the PAD plate end) and had a look. Nothing really to see. It has the 12 square sections that are the sensor elements on plastic film and a big rubber molding for the PAD buttons. No obvious damage.

I then did something weird but I wanted to see how the pads sensor elements were constructed as it looked just like the internals of a some kinds of PC keyboards (they have a similar looking plastic film and flexible PCB though the nanoPAD uses Force Sensing Resistors); I peeled back the top layer of plastic that was over the first two buttons – JUST the first two buttons and peeled it back so that I didn’t crease the plastic. It has a lot of glue holding it down at the start and I wondered if this could be some issue but it peeled back OK (bit of force needed) and exposed the first two PAD elements (i.e.  the ones closest to the X-Y controller).

I then smoothed the plastic film back into place and plugged the PAD cable back into the PCB.

I tried it and it worked !

It is velocity sensitive and I correctly got events on all PADs with a very light touch yielding say a velocity value of 25 and a bash yielding a velocity of the maximum of 127. I hit them very hard with fingers and very light and they all seemed to be the same sensitivity.

I re-assembled; PAD metal frame screwed back, pushed back copper shield onto PAD metal frame, screwed case back on and added rubber feet into place.

Still worked. I was very pleased.

I could not see what the heck was actually really wrong in the end though I had cleared the fault. Maybe that glue was holding in moisture from manufacture ? Who knows as the problem is now gone and it doesn’t seem to be coming back for my unit yet.

I’d looked around for fixes to the Korg nanoPAD and I saw a number of people with the PADs failing even after light (or in my case practically no)  use. So I suspect a manufacturing defect and as far as I can see Korg seem happy to replace the units if you report this in warranty period so there are no real tears here except loss of your time.

It could be that the fix I described above i.e. peeling back that top layer of the plastic film on the start of the PAD sensor assembly works for you too and there is no harm in trying this if you have a broken unit out of warranty.