Discussion about the Korg PolySix synthesizer

So, really, anyone with experience please jump right in and give some 
insight because I'm near my wit's end.  It makes me very nervous to 
remove the processor everytime I take out klm367 to work on it.

So, I have new sockets in there for ICs 30 and 31.  I have brand new 
wire making every connection from IC 31 and R 17.  I checked every 
connection to make sure they're good.

What's happening is that nothing related to programming a sound works 
or responds to a knob turn or switch switching.  When I turn it on 
and off it gives me a light show on the patch panel then selects a 
random patch with alterations.

Why would this happen?  Why after months of working fine, all of a 
sudden I get this crap?

It almost beings to sound like the RAM chip went bad.  I've encountered 
'367s with dead RAM before.  If you can, using a voltmeter check the power 
pins of the RAM chip (pins 9 and 18) with the power on and then with the 
power off.  On, it should read around 4.5 volts.  Off, it should read 
around 2.5 to 3 volts, depending on battery type.  I've seen where the 
pins of a 5514 sram chip corrode, or worse, the corrosion enters the chip 
body through the metal of one of more pins and eats the metal of the pin 
away inside the chip even though the pin looks good.

  Another test is to load a set of voices from a tape or wav file into the 
P6, then do a verify on the same tape/wav file to see if things got 
scrambled when trying to store.  Other possible problems are the 4011 
(IC25) that controls the write access to the ramchip, or a dead/overloaded 
bus buffer (IC30/IC31).

Crow
/**/

When on, the 5514 gives me around 3.9 volts and off it reads about 
1.9.  Funny, though, that section looks clean and even the legs look 
good (shiny metal).  I only did a quick test the other night and 
haven't removed 367 (again) to check for more continuity problems.

I was looking for replacements online but I mostly got a lot of links 
to video-game repair.  Here is a list of comparable replacements as 
far as I can determine:

Toshiba 5514
Harris HM6514, National 6514, Fujitsu 6514
NEC 444, RCA 5114, Hitachi 4334

Is it safe to assume any one of these can replace the 5514?  

The patch and bank section of the programming controls lock up on me 
so I'm not able to test whether I can load in data.

Thanks.



--- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
> 
>   It almost beings to sound like the RAM chip went bad.  I've 
encountered 
> '367s with dead RAM before.  If you can, using a voltmeter check 
the power 
> pins of the RAM chip (pins 9 and 18) with the power on and then 
with the 
> power off.  On, it should read around 4.5 volts.  Off, it should 
read 
> around 2.5 to 3 volts, depending on battery type.  I've seen where 
the 
> pins of a 5514 sram chip corrode, or worse, the corrosion enters 
the chip 
> body through the metal of one of more pins and eats the metal of 
the pin 
> away inside the chip even though the pin looks good.
> 
>   Another test is to load a set of voices from a tape or wav file 
into the 
> P6, then do a verify on the same tape/wav file to see if things got 
> scrambled when trying to store.  Other possible problems are the 
4011 
> (IC25) that controls the write access to the ramchip, or a 
dead/overloaded 

> bus buffer (IC30/IC31).
> 
> Crow
> /**/

I use the HM6514 all the time for repairs and new boards alike.  They 
are $3 ea from Jameco.

  However, if the programming controls 'lock up' it still sounds like the 
CPU (IC22) is crashing due to either a bad connection or the part itself 
is failing.

Crow
/**/

On Wed, 28 Jul 2004, toorglick wrote:

> When on, the 5514 gives me around 3.9 volts and off it reads about 1.9.  
> Funny, though, that section looks clean and even the legs look good
> (shiny metal).  I only did a quick test the other night and haven't
> removed 367 (again) to check for more continuity problems.
> 
> I was looking for replacements online but I mostly got a lot of links to
> video-game repair.  Here is a list of comparable replacements as far as
> I can determine:
> 
> Toshiba 5514
> Harris HM6514, National 6514, Fujitsu 6514
> NEC 444, RCA 5114, Hitachi 4334
> 
> Is it safe to assume any one of these can replace the 5514?  
> 
> The patch and bank section of the programming controls lock up on me 
> so I'm not able to test whether I can load in data.
> 
> Thanks.

Is it possible that if a good trace is jumped that the processor is 
getting *too much* input?



> 
>   However, if the programming controls 'lock up' it still sounds 
like the 
> CPU (IC22) is crashing due to either a bad connection or the part 
itself 

> is failing.
> 
> Crow
> /**/