Vintage Synth Repair

Keyboard scans typically use an X/Y scan much like a computer keyboard, in groups of 8 and every 8th key.  Voices repeat repeat by the number your model has available, ie a 4 voice would repeat every 4.  So count up by eights and a number will repeat in a pattern.  If any of that number start playing it is not the key scanner, but an open between one point that works and the ones that do not.




On Saturday, January 18, 2014 2:41 AM, Keith Niver <kaniver@...> wrote:

 
>Is it like every 6 notes or 8 notes or entirely random? It could be just dirty contacts.
>Keith
> 
>From:vintagesynthrepair@yahoogroups.com [mailto:vintagesynthrepair@yahoogroups.com] On Behalf Of mpigott2@...
>Sent: Thursday, January 16, 2014 8:31 PM
>To: vintagesynthrepair@yahoogroups.com
>Subject: [vintagesynthrepair] Cetain notes not sounding on JX-3P
> 
> 
>I went to play my JX-3P and noticed certain notes not in a row are not sounding.
>Didn't have a piece of paper but they were in the lower registers.
>None were in a row.  It was like E not sounding then C, etc.
>
>Put it in test mode and all oscillators are cycling through, but these same notes are not sounding. Isn't there an IC that distributes or scans the keyboard and this is at fault?
>
>Any ideas?
>
>
>