If your grinder has begun to clump, there are a few things you can do to fix the problem. First, try running the grinder through a cycle with no coffee beans. This will clear out any debris that may be clogging the blades. If that doesn't work, you can try disassembling the grinder and cleaning the blades. Be sure to clean all the nooks and crannies, as coffee grinds can hide in small spaces. Once the blades are clean, reassemble the grinder and give it a test run. If it's still not working properly, you may need to replace the blades.