I have a Eureka Zenith 65 E grinder that I took apart the burrs to clean the other day. Now the grinder will only grind on coarser settings. If I try to go any finer, it just does nothing. Any thoughts on troubleshooting?

Remove the upper (fixed) burr, and then use the grind adjustment knob to raise the lower burr upwards (finer). You'll have to fiddle a bit as if you raise the lower burr up too much you won't be able to re-install the upper burr. That should do it.

What do you mean it does nothing? So with no beans if you start on coarse and then turn it to fine can you still hear the burrs spinning all the way till you here the burrs touch(chirp)? If you repeat, but with beans does do the burrs stop spinning at some point? Or are you just setting it to fine with beans in, the burrs never start spinning? Hard to give you any input without a little more info