Yamaha CS80

I'm sorry I can't provide any further details about where the grounds join together or join back to the grounds from the PSU; I just don't remember.  One detail I can provide is that it was power rails measured with respect  to the metal chassis that would change depending on what keys were played, so for example that +11V you are measuring would move around depending on what key was last pressed. That 2K ohms measured from the Mcard Gnd to the +/- 15 V ground sounds fishy to me, but you'll want to confirm of this is correct/expected before you change/add any connections, lest you cause even more damage.


jkjelec

>     On March 15, 2017 at 8:38 AM "'LucidSound' lucidsound@... [yamahacs80]" <yamahacs80@yahoogroups.com> wrote:
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>     I’m keen to know where the grounds should be linked. I’m seeing the M card ground is 0.3 ohm with respect to the logic power ground, but around 2k to the +/-15V ground. I’m guessing that shouldn’t be the case?
>      
>     Lucid.
>      
>     From: mailto:yamahacs80@yahoogroups.com
>     Sent: Wednesday, March 15, 2017 4:03 AM
>     To: mailto:yamahacs80@yahoogroups.com
>     Subject: [yamahacs80] One more thing...
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>      
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>      
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>     Hi Lucid Sound,
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>     I remember that in the case i mentioned, some of the voltages I measured would change unexpectedly when I played up and down the keyboard, thus giving me the clue that the analog and digital systems had become "floating" relative to each other.
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> 
>     Kyle
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>     jkjelec
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>     
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