What you want is for the bottom block to click when you pull the main sheet on and when you release the rope the claws in the middle pully should try and grab hold of the rope and not spin with it. The top block is just a block so that you can get more of a advantage, it doesn't have a clicky thingy. If the bottom block clicks and when you release it it doesn't gip and the pulls spins then yes you have a broken block. Hope this helps.
