I have one old A2000 keyboard that does the same thing, and I found out that mine is shorted, so kinda dangerous.
The way I found out, I booted w/o the keyboard, and it was fine, but when I plugged in the keyboard, the Amiga crashed.
I took it apart and found xtal was loose, I'm not sure what else is wrong, but for sure, I'm not plugging that keyboard again!
