A few weeks ago I had a cuttlebug meltdown. It stopped working. I got my wonderful sweetie to take care of it for me. But the rollers were not moving when I moved the handle so I couldn't emboss anything. What it's all called I have no clue, but he said it's a problem that will probably happen again in the future so he suggested I take pictures to show how to fix it. It was a screw that popped off and I could hear rattling in it.
Step 1 - pop off the side opposite where the handle it.
Step 2 - Loose screws you'll find that need to be put back on so be careful they are small
Step 3 - Put them back on and use the allen wrench that came with it
Step 4 - Then just pop back on the side again and all should be good.
Good luck! Hopefully it doesn't happen, but I've heard many people say they've had something like this happen. So I know it's common since it's one of the maintenance things that will mess up. I figure it will happen again the future so better to be prepared and since it's a simple fix, I won't freak out.