Behringer V-Tone Gmx110 don't change channels

[Blk4evr]

Help me please, After a few minutes of use, the amp won't change between channels, go direct to the tuner, it's still happened with the amp button or the footswitch. The amp need to be powered off and on in order to get out of the tuner, but still not changing channels.
Sometimes when the amp is rebooted, the displays shows a "t" and sounds or a "t1" and doesn't sound

[The Dude]

You'll have to verify. I'm not sure, but I think the GMX212 is basically the same. If so, this schematic should match or be close enough. If not, that's all I have.

GMX212.pdf

It sounds like the problem is heat related. I'd start by seeing if anything is getting hot, or try to narrow it down with some cold spray. Also check that your power supply voltages are holding up. You could have a regulator that's failing after warmup.

[Enzo]

I have both, and though some parts move around the page a little, they do look REAL similar. And your file includes the FX card, where the switching lives. I believe it is the same card.

The switch inputs are wired directly to the 80C32 chip.