Hi Lucid Sound,

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.

Kyle

jkjelec

开云体育

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