Left channel of a stereo pair has lost ~60db of gain

This is the second pair of stereo channels I have doing this.

This one is coming from a keyboard. I have to unpair the gain on these stereo channels because all of a sudden I’ve lost ~60db in the left channel. The gates are still paired so I still have a meter showing in that box, but the input for the left is way way down. Gaining it up to parity with the right channel creates a lot of overhead noise, as you might imagine.

Approx. 10-year old Qu-32. Never serviced. Firmware is up-to-date.

And you’re absolutely sure it isn’t the cabling, DI or keyboard (pansettings maybe ?)itself ?

Giga