Yamaha CS80

Sounds like a tricky one this. There is no point in replaceing the 
151's is it is going to just burn them out, so I would sugest that 
you reduce the area of the problem. Check the power rail caps and 
look for any high voltage comming into the voice card in the EG area 
as well as the filter. Use a working voice as referance.

Let me know how you get on :)



--- In yamahacs80@yahoogroups.com, Stephen Teller <s.teller@...> 
wrote:
>
> This list  seems to be the only place to get the goods.............
> 
> 
> When no signal from a voice card is first traced to a VCA, where 
the  
> signal doesn't show, what methods do you use to troubleshoot 
where  
> and how it's being pulled down and overheating several chips in 
the  
> surrounding path. Obviously its a current draw issue, but I don't  
> want to damage more components in the process of replace and 
retest.  
> (When replacing just the first VCA chip that has no output, it  
> overheats the replacement if you leave it in circuit) IC3 and 4 
are  
> specifically troublesome, as they are common output.
> 
> 
> Thanks!
> 
> Stephen Teller
> 
> [Non-text portions of this message have been removed]
>