Necchi 215A won't pick up bottom thread

Question

I got this machine new a few days ago, it was already threaded but the top thread was only a short length. when I needed the machine to pick up the bottom thread again it just won't it doesn't catch it in the loop at all, sometimes it doesn't even make a loop. I have threaded the top thread down to the needle as per the book, and have loaded the bottom case with the bobbin as per the book also, still no joy. It's so frustrating - please help!