sounds to me like you need a scope and perhaps a qualified technician.
--- In yamahacs80@yahoogroups.com, Stephen Teller <s.teller@...> wrote:
>
> We've been trying to sort this one out for awhile- please help Mr.
> Spong... : )
>
>
> 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]
>