Luckily, I have with me a debug tool from the future: the Z3660 is an open hardware accelerator which can optionally emulate a full 68040 CPU with UAE's open-source JIT running on a modern ARM core:
https://github.com/shanshe/Z3660
I bought this baby at AmiWest for my A4000, but now it will come handy to probe the A3000 PCB from a working system.