I've been waiting some time before answering and tried in the meanwhile to read as much as I could about digital circuits, to be sure I wasn't alarmed for nothing. What I can now deduce is that the processor could be stuck somewhere. The only digital signal I see are less that 1v in amplitude and mixed with noise.

This is something that happened last week, the synth was almost working, maybe measuring around I bridged something causing the fault?

So sad!