We get a lot of spools back into the service department (we sell even more!). Over half of them turn out not to have an issue with them; rather, they have been set up or misused.
A common complaint is that the overhead reel does not have the specified amount of drag.
Once tested, a very common reason for this is that the braid is freely rotating around the spool because it hasn't been put on correctly. This is very rare (as in, I haven't seen it happen yet) when we are spooling reels, but it is commonly seen when a customer does it themselves, or 'the local store' (or mate) does it for you.
A quick way to test this is to put a small piece of tape on the braid and make a reference mark on both the tape and the spool itself.
Lock the drag up tight and pull hard on the braid. If the dot on the braid moves, but the dot on the spool's edge doesn't, the braid is spinning around the spool.
If this is the case, the braid must be removed and respooled. We can help with this, but we would appreciate it if you do this quick test before sending it back as faulty.