Turning off PCM sound generator?

I think it is a bit more complicated than that, I'm using a Yamaha RS7000 as a sequencer and not a computer so usb is not an option.

The RS7000 has 2 midi outs but I need to sequence and send clock to more machines and 2 of them don't have MIDI thru so it is a big problem if I use one of the MIDI outs just for the GAIA, another problem is hearing that piano sound when I send a MIDI to another channel by mistake.

I guess the only solution is what Grauw sugested but as he said It costs a bit and it brings more problems.

Or maybe I get lucky and Roland releases a firmware that can fix this...

I wonder if there is a way to open the machine and just kill the GM Chip?

Just connected my groove box to GAIA on MIDI IN/OUT and, indeed, the GM part switch works after GAIA upodate to version 1.03.

The procedure for setting the System parameter is as follows; the parameter
is called "GM Part Switch".
1. Hold down the [CANCEL/SHIFT] button and press the [VLINK]
button to enter the System Setting mode.
2. Hold down the EXT IN [CENTER CANCEL ON] button and
press the [EFFECTS ON/OFF] button to switch the "GM Part
Switch" ON and OFF.
* You can confirm the parameter setting by verifying the following light
condition while holding down the EXT IN [CENTER CANCEL ON] button.
[EFFECTS ON/OFF] lights up: GM Part Switch is ON.
[EFFECTS ON/OFF] lights down: GM Part Switch is OFF.

Have fun :)

Finally a solution to this!
Roland has listened...

To turn off the PCM sounds:
1) update to latest firmware (at the moment 1.0.3)
The procedure for setting the System parameter is as follows; the parameter
is called "GM Part Switch".
2) Hold down the [CANCEL/SHIFT] button and press the [VLINK]
button to enter the System Setting mode.
3) Hold down the EXT IN [CENTER CANCEL ON] button and
press the [EFFECTS ON/OFF] button to switch the "GM Part
Switch" ON and OFF.
* You can confirm the parameter setting by verifying the following light
condition while holding down the EXT IN [CENTER CANCEL ON] button.
[EFFECTS ON/OFF] lights up: GM Part Switch is ON.
[EFFECTS ON/OFF] lights down: GM Part Switch is OFF.

SWEEEEET

Finally!
I actually sold my Gaia since I started down-sizing my rig and chucked my Computer and DAW. Now I have to chain the midi together with a thru box and using thrus on the synths. Good to see Roland now put the option on the Gaia to turn of the GM sound set. I am not sure if I would buy a Gaia again though.

I love it, it was great that Roland made this option available.

Thankyou so much for this.
The info has stopped me tearing what's left of my hair out

Also big thanks from my side! This solved big issue on my side.

Is there a cheat sheet for these arcane command sequences?
May be my age but pretty sure I'll never remember this (useful) info.
-Sean

Check this page:

https://rolandus.zendesk.com/hc/en-us/articles/201973589-GAIA-SH-01-How-to-turn-off-GM-tones?fbclid=IwAR3OYPHpOoQrb4PLrkR3CN3qc3d89OiZYYBRr3rNygftxHF5ErJ2_06L3cM