Yamaha CS80

Still checking voltages here - so I have an update on this fault. It seems the voltage on CP6 varies quite a bit... but all cards vary 'in unison'... so my origianl reading of 1.4 volts is just one of many values that appear at that point. But this faulty card is always a lot lower in value. Could that be a clue as the problem? I am just hoping it's not a VCO chip gone - yet AGAIN..!

I also have a filter problem on another M card. On certain voices (it is more apparent on Strings presets than Brass...) the filter is very 'thin'. I am getting a constant 5volts on pin 8 of IC1, the VCA - where the other good cards have a varying voltage. Would this indicate a faulty VCA chip?

Cheers,
TOM 



--- In yamahacs80@yahoogroups.com, "Quazimodo" <noddyspuncture@...> wrote:
>
> Hi guys, wonder if anyone has had this one before... thought I'd ask first in case anyone could point me to it.
> 
> I just started to have a go at my out-of-tune 'M' card.
> CP6 reads 0.5volts - when all the others read around 1.4volts
> 
> The voice is out of tune, and low in pitch. When I play that voice and then measure CP6, the pitch rises due to my meter prong's contact.
> 
> (I was thinking one of the FET's or IC7..?)
> 
> Cheers,
> TOM
>