The Amiga generally had 2 types of keyboard connector, the large 5-pin DIN and the small 6-pin mini-DIN. While the PC equivalents fit, they don't speak the same language and so it just won't work. However, the adaptors for PC keyboards that convert 5-pin to 6-pin and vice versa work on the Amiga as well, so maybe that's all you need? They're usually quite cheap...
