Could my 4000 just be "locked"?

[Castellen]

The lock function only disables keyboard and mouse movement input.
You can still input mouse clicks, and the system should still boot as normal.

The lock function works when the circuit is open, so if one of the wires is broken or the keyswitch plug is removed, then it will disable the lock function.

[Castellen]

To fault find the rest of it, just check all the power rails are present (you only really need +5V to make it work, +12V if you want to use drives).

Try a different CPU board, and check the two clock source jumpers are in the correct position.

If using an A3630, make sure you have the 25MHz(?) clock signal on both clock source jumpers.

Check both ROMs are correctly seated and don't have bent pins due to misinsertion.  Make sure the two ROMs are in the correct sockets :-P

If it's socketed, try a different 2Mb SIMM for the chip memory.  Remove all the fast mem SIMMs for now.


That's about as far as you can go without more serious test equipment.

The board should boot into the purple "insert disk" screen with only a 5V supply and nothing fitted to it except some chip mem.