Also, rebooting with Ctrl+Amiga+Amiga results in a permanent black screen. I inspected the reset logic, and /CPURST remains low forever.
I can't tell whether there's a problem with the A3000, but other Z3600 owners confirmed it shouldn't happen.
Debugging all these quirks would be much easier with an oscilloscope. I should take this project to a shop with proper lab equipment...
#commodore #amiga #retrocomputing #vintagecomputing #electronics