The Kawai & Teisco Analog Synths Group

Can you describe the problem again ?

As far as I understand the problem is dead tones -
which doesn't come up at all when in Poly 8 mode (all keys respond 
and plays ok) and only exist when in Poly 4 mode, where the first 4 
keys pressed will play and the next 4 won't ?


--- In kawai_sx210@yahoogroups.com, "Mark Daborn" <darkest.yugo@n...> 
wrote:
> Hi, as this whole problem with my machine is due to battery 
leakage, i have already removed the nasty old Ni-Cad
> and replaced it. Ic's 7 and 8 have been replaced and most of the 
tracks  in the area  hard wired. All other tracks have been tested 
for continuity and appear okay.
> 
> The behaviour of the machine still suggests possibly a ground issue 
or a defective IC (or IC's!!). 
> 
> When played in poly mode we found there was a regular pattern to 
the silent notes. In poly 4 mode it was even more obvious. Basically 
4 notes on (as we played up the keyboard) then 4 off. However, 
cycling through the 8 voices when playing one key (that worked) 
showed no sign of a defective voice.
> 
> We have already eliminated the keyboard as a source of the problem.
> 
> It's looking likely that as it's getting the instructions to play a 
note ok, and the sound generation side of it is okay, the problem 
must lie somewhere  in between.
> 
> The plan, therefore, was to remove the possibility of the EPROM 
being corrupted, which has already had a new socket.
> 
> My friend has taken the service manual and is going to read it 
cover to cover hoping for divine inspiration!
> 
> Thanks for your help!
> 
> Mark.
>   ----- Original Message ----- 
>   From: gil_we 
>   To: kawai_sx210@yahoogroups.com 
>   Sent: Sunday, October 02, 2005 12:10 AM
>   Subject: [kawai_sx210] Re: Can anybody please help???
> 
> 
>   Did you read my last response ?
> 
>   Are you rewiring the board ? did you replace all components at 
the 
>   battery area ?
> 
>   The behavious could be due to a defected EEROM, if the battery 
hasn't 
>   leaked... but as this is the situation - look at the battery 
leakage 
>   as main suspect.
> 
> 
>   --- In kawai_sx210@yahoogroups.com, "Mark Daborn" 
<darkest.yugo@n...> 
>   wrote:
>   > Hi,
>   > 
>   > The restoration of my SX-210 continues furiously.
>   > Today my techie friend and i had the thing in bits testing and 
>   probing as much as we could.
>   > We eliminated quite a few components from our investigations 
but 
>   have reason to doubt the contents of the EPROM.
>   > 
>   > Does anybody have a copy of the program or know where i might 
find 
>   one? I have had a search on the net but as yet
>   > not found anything.
>   > 
>   > Could someone please help? Today my SX 210 almost made a 
sensible 
>   sound and it's boosted my efforts to fix it.
>   > I didn't realise how amazing the ensemble sounds!
>   > 
>   > Thanks for any help you can provide,
>   > Mark
> 
> 
> 
> 
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