Blocks of micro korg keys not working

[Dbmiller8]

I am new on here. I have an old micro korg that has a problem with keys C#3 thru E4. They don’t work. I was thinking the motherboard may be faulty because there are a bunch of other buttons that are not working(arpeggiator on/off, octave shift up/down, etc). But looking at the schematics, it looks like C#3-G#3 and A4-E4 on the daughter board are separate circuits on that board. So now I am thinking it is the daughter board. I tried cleaning the daughter board contacts(there was some corrosion on some of the pads) but the problem persists. In looking for a replacement motherboard, I am hopeful it is the daughterboard since mother boards seem impossible to find. Any help would be appreciated. Thanks in advance.

[OpAmp]

Hi,

C#3-G#3 use all the BR02 and MK02 lines, while A4-E4 use all the BR03 and MK03 lines. That can be a clue.
You can maybe try to meausure pass through's on the daughter card with a multi meter.

Further, I'm not sure it is worthwhile to buy new daughter or motherboards for a micro. No idea how much you can save vs a new or working second hand one.


Have fun.

[Dbmiller8]

Thanks OpAmp. A new motherboard is too expensive to justify not just buying a new micro for sure. I found a daughterboard for about $50 delivered. I am a hobbiest type of player so $50 is ok. $400+ is not. I have a new daughterboard en route. The weird ‘other issues’ leave me with some doubt that the new board will make it functional again but if not, I may just part the thing out. It is in pretty good shape for a 15 year old keyboard that my kids used to ‘play’ with. Thank you again for your suggestions. For my own knowledge, I will probably compare the passthrough on both boards. Knowledge is never a bad thing. Take care.