[sdiy] Various and sundry keyboard problems

[rkmoore at memphis.edu]

Hi Tim,

I would definitely suggest opening the ESQ-1 up, pulling out the
keyboard, and inspecting the contact rail solder joints.  When I worked
as a repair technician for a couple of years that was a pretty common
problem with Ensoniq keyboards of this type.  Do this before exploring
more exotic and less likely problems with the scanning electronics, etc.
 The fact that the notes won't cut off when triggered fortifies the idea
of a faulty keyboard rail.  That ensoniq has 'key up' contact and a 'key
down' contact.  Problems with either one can result in notes triggering
only intermittently, velocity problems, or note release problems.  

Richard Moore

Oh yeah, thanks to everyone, except Harry :),for the cable organizer info. 

----- Original Message -----
From: Tim Parkhurst <tparkhurst at siliconbandwidth.com>
Date: Friday, June 24, 2005 12:32 pm
Subject: [sdiy] Various and sundry keyboard problems

> Hi All,
> 
> Thanks for all the responses. Lots of good info, and I appreciate 
> the help.
> Here’s kind of a quick summary:
> 
> ESQ-1
> Unfortunately, a reset didn’t cure the keyboard problem (set of 
> eight or so
> ‘dead’ keys). The bad keys will sound occasionally, but they are 
> very quiet,
> and they sustain forever (the notes sound quietly until I play 
> enough notes
> on the good keys to ‘steal’ the voices and shut them off). It 
> could be
> several things, but I’ll have to take it apart to really check. In the
> meanwhile, it’s working perfectly through the MIDI in.
> 
> U-20
> Lots of suggestions here. I'm pretty sure this isn't a 'soft 
> problem' that
> could be cured by a reset. MIDI in works fine, and sometimes the U-20
> keyboard will trigger twenty or thirty times in a second when I 
> press a key
> (again, a neat effect if you could control when it appeared). I’ll 
> go back
> in and yank the thing apart again (PITA because the keys all come out
> separately and are not held by a common, removable bracket), and 
> give the
> PCB contacts and the contact strip ‘carbon buttons’ a good 
> cleaning. I may
> even try the acetone thing, but I’ll check it on the contact strip 
> materialfirst to make sure there are no adverse effects. You know, 
> acetone or some
> similar solvent may be what I need to rejuvenate the scratched 
> resistortracks in those pesky ARP slider pots too. Use just enough 
> to ‘re-flow’ the
> resistive material and cover the scratches. If cleaning the U-20 
> contactstrips doesn’t work, I may try to attach new carbon buttons 
> from other
> switches (good suggestion, that one). Otherwise, I’ll dig up 
> replacements.Got a couple of links/offers on those too, so thanks 
> also to those who
> offered. Again, the U-20 works fine through the MIDI in, but the 
> keyboard is
> really nice (when it works) and I like the arpeggiator and ‘chord 
> memory’features (haven’t really tried, but I think those don’t 
> work though MIDI). 
> 
> Thanks again, Group!
> 
> 
> Tim (Bad keyboard! Now go to your room!) Servo
> 
> "Imagination is more important than knowledge." - Albert Einstein
> 
> 
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> 
>
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