Discussion about the Korg PolySix synthesizer

BTW,
  
    It's generally not a good idea to solder anything in a device that is powered up.
Lots of soldering stations connect the soldering iron tip to earth ground, so if you 
connect that to a point in the circuit, you are shorting it to ground.   Also, it's just
safer to do any kind of mod, component removal, etc while power is off, so that if
you accidentally touch something near where you are working with the soldering iron, pliers, etc,
you don't risk shorting something out.

   IMO, setting the reset trip point is not "jumping the gun".   It shouldn't depend on whether
the rest of the circuit is running, except for the fact that the 5V supply exact voltage will 
vary a bit with load (what the CPU is doing).   But the change should be small.   And setting 
the trip point would confirm that the reset circuit is now working correctly and will keep reset
from glitching on later on when you are trying to troubleshoot something else.   But I still suggest
that you measure the 5V supply as you connect and disconnect the 57K ohm (47 +10) resistor.
If it's not changing for some reason, then setting the trimpot won't work.

Something that I use all the time is a small piece of wire, maybe 8-12" long, with a little spring-loaded
clip/hook on each end.   This would be perfect for connecting and disconnecting the resistor to those
posts.  No soldering required, and you can do it with power on.   There are two sizes of clips/hooks
that are easy to get.   minigrabbers are the smaller size.  I have maybe 4-5 wires with each size 
on them.   The larger size is good for connector pins or clipping onto typical DMM test leads.
The smaller size are better for clipping on the pins of an IC.   I like to use these leads when monitoring 
pins of a chip with a scope, as it's a little safer than using a scope probe.   If you are using a probe and
it slips and short two pins of the chip together, you can damage a chip that may be tough to replace,
like the 8048, for instance, since it has P6 code in it.

   These leads are very cheap on ebay.

     Bob

--------------------------------------------
On Sat, 2/13/16, jw_dewdney@yahoo.com [PolySix] <PolySix@yahoogroups.com> wrote:

 Subject: Re: [PolySix] Re: PROGRESS!!!!
 To: PolySix@yahoogroups.com
 Date: Saturday, February 13, 2016, 1:41 PM
    
       
       okay Bob... thanks for the calibration info.
 It's much more informative than the service manual, i
 did it by soldering the resistor across the connector pins
 inside the connector while the polysix was OFF. And then
 unsoldering it while ON....  So it makes more sense to me
 why it wouldnt work (unless a deeper problem is still at
 play here as Roman suggested). Perhaps i shouldnt be trying
 the calibration routine yet even?
 
     
      
 
     
     
 
 
 
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