Yamaha CS80

Thanks for the reply Crow

My tech is wondering if you could have possibly meant the 4013's from a 
TSB board instead of the 4050's from the KAS board?
He can't see on the schemo where IC4 & IC5 on the KAS ties into the 
aftertouch though he's having trouble enlarging the image.
We think we might have had a bad run of 4013 chips.

Can you please confirm either way?

thanks so much

Stephen Teller
Stephen Teller Music
805/480-9614
s.teller@...
www.stephentellermusic.com




On Apr 4, 2005, at 9:36 AM, STEPHEN TELLER wrote:

>>
>> Message: 2
>>    Date: Sun, 3 Apr 2005 22:29:30 -0400 (EDT)
>>    From: The Old Crow <oldcrow@...>
>> Subject: Re: CS80 Repair Question
>>
>>
>>   Educated guess: replace IC4 & IC5 on the KAS board.  It sounds like 
>> a
>> note encoder line (_N3, to be exact) is not operating correctly.
>>
>> Crow
>> /**/
>>
>> On Sun, 3 Apr 2005, STEPHEN TELLER wrote:
>>
>>> 	As I scope the A,B,C lines, I notice pin 9 on all 4051's is 
>>> inactive,
>>> regardless of playing multiple keys, or activating after touch. Pins 
>>> 10
>>> & 11, become active under certain states. I have gone back through 
>>> the
>>> immediately obvious circuitry and even re -replaced the chips 
>>> involved,
>>> to no avail.
>>> 	 My question is, if you probe a working CS80 at pin 9 of any of the
>>> 4051's, is the line active? If not, do you have a viable approach to
>>> this issue ?
>>
>>
>>