Yamaha CS80

Hello everyone.

I�m newbie here and cs80 and cs60 owner from Finland. Second cs80 
should come from London next week. I wonder if i find here someone who 
can solve my problems with cs80. The problem is that in ch-2 voice #4 
doesn�t sound at all? In ch-1 it�s normal but ch-2 it�s like muted. 
Also voice #6 sounds very loud, like only aftertouch could hear very 
loud but normal sound is quiet? I have repaired all the downstears ic-
chips and add ceramic-capasitors under KAS-board for every chips like 
oldcrow adviced. So total of over 50 new chips! That�s why i think the 
main problem is somewhere else. I have think that maybe M-board-5 and 
6? Please help me if someone understand my problem cause can�t find 
any help from here Finland! Thank you for your excellend sites.
ESKO

--- In yamahacs80@yahoogroups.com, "eskojramo" <eramo@...> wrote:
>..Sorry, I meaned voice #5! Voice #4 working property!..

--- In yamahacs80@yahoogroups.com, "eskojramo" <eramo@...> wrote:

     Any ideas?

eskojramo wrote:
> Hello everyone.
>
> I\ufffdm newbie here and cs80 and cs60 owner from Finland. Second cs80 
> should come from London next week. I wonder if i find here someone who 
> can solve my problems with cs80. The problem is that in ch-2 voice #4 
> doesn\ufffdt sound at all? In ch-1 it\ufffds normal but ch-2 it\ufffds like muted. 
> Also voice #6 sounds very loud, like only aftertouch could hear very 
> loud but normal sound is quiet? I have repaired all the downstears ic-
> chips and add ceramic-capasitors under KAS-board for every chips like 
> oldcrow adviced. So total of over 50 new chips! That\ufffds why i think the 
> main problem is somewhere else. I have think that maybe M-board-5 and 
> 6? Please help me if someone understand my problem cause can\ufffdt find 
> any help from here Finland! Thank you for your excellend sites.
> ESKO
>   
Hi Esko.

Welcome to the group!  I wish we could have some kind of gathering and 
all meet and fix up our gear, like the AH meetings (or classic car 
groups), but everyone is so spread out, and it would be insane (and cost 
a fortune) to have everyone bring their CS-80s to one place.  We'd 
probably look so suspicious we'd be raided by Homeland Security :^)

I assume you have test equipment, including a multi-meter and an 
oscilloscope.  I'm a little confused.  How did you already replace all 
the CMOS chips if you aren't getting the keyboard until next week?  Did 
you go to London to work on it?  Also, another thing about the 
"Downstairs" boards and replacing CMOS.  There are more CMOS 
chips/missing bypass caps on the two KBC boards in the upper rack.  I'm 
pretty sure Crow's (great) guide didn't include those boards, which is 
why I was short some parts and had to order more.

Anyway, back to your keyboard.  It could certainly be the M boards.  It 
should be pretty easy to trace with a 'scope.  The card that makes no 
sound could be a bad trigger.  I think the easiest way to troubleshoot 
would be to pull the bad card from the frame, along with the same 
M-board from the other channel.  Make sure you don't short the boards to 
anything!  Set the panel to be the same for both channels and just start 
tracing the good board vs. the bad one.  There's lots of trimmers that 
could be affecting volume.  Just go through the adjustment procedures, 
or isolate first by comparing the boards (compare envelope outputs, 
outputs of the various VCAs, etc).  Nothing magic, just signal tracing.

Good luck & let us know how it's going.

 David



-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.385 / Virus Database: 268.4.1/307 - Release Date: 4/10/2006

--- In yamahacs80@yahoogroups.com, David Rogoff <david@...> wrote:  
> Hi Esko.
> 
> Welcome to the group!  I wish we could have some kind of gathering 
and 
> all meet and fix up our gear, like the AH meetings (or classic car 
> groups), but everyone is so spread out, and it would be insane (and 
cost 
> a fortune) to have everyone bring their CS-80s to one place.  We'd 
> probably look so suspicious we'd be raided by Homeland Security :^)
> 
> I assume you have test equipment, including a multi-meter and an 
> oscilloscope.  I'm a little confused.  How did you already replace 
all 
> the CMOS chips if you aren't getting the keyboard until next week?  
Did 
> you go to London to work on it?  Also, another thing about the 
> "Downstairs" boards and replacing CMOS.  There are more CMOS 
> chips/missing bypass caps on the two KBC boards in the upper rack.  
I'm 
> pretty sure Crow's (great) guide didn't include those boards, which 
is 
> why I was short some parts and had to order more.
> 
> Anyway, back to your keyboard.  It could certainly be the M 
boards.  It 
> should be pretty easy to trace with a 'scope.  The card that makes 
no 
> sound could be a bad trigger.  I think the easiest way to 
troubleshoot 
> would be to pull the bad card from the frame, along with the same 
> M-board from the other channel.  Make sure you don't short the 
boards to 
> anything!  Set the panel to be the same for both channels and just 
start 
> tracing the good board vs. the bad one.  There's lots of trimmers 
that 
> could be affecting volume.  Just go through the adjustment 
procedures, 
> or isolate first by comparing the boards (compare envelope outputs, 
> outputs of the various VCAs, etc).  Nothing magic, just signal 
tracing.
> 
> Good luck & let us know how it's going.
> 
>  David
> 
> 
> 
> -- 
> No virus found in this outgoing message.
> Checked by AVG Free Edition.
> Version: 7.1.385 / Virus Database: 268.4.1/307 - Release Date: 
4/10/2006

>Hi David and thanks for your reply.

I ment that the problem is for my first cs80, second cs80 should come 
this week. I start to testing right away like you told. Thanks a lot.