Whenever you find small cracks in one of your cymbals do not think you have to throw it away. The earlier you notice the crack, the better you can prevent it from becoming a real issue.
Small cracks usually do not have a noticeable effect on the sound of a cymbal. In order to check for cracks let your fingers slide along the edge of the cymbal. That way you can find the cracks before you can hear them.
The best way to deal with those small damages is to simply cut them out. So you prevent them from getting bigger and starting to influence the sound a lot more.
But even bigger cracks can be cut out the same way.
Simply keep in mind that the more material you have to cut out, the more it will influence the sound of the cymbal. Even if the basic characteristics of the cymbal stay the same, you will notice a change in matters of sustain and tone.
The first thing to do is to drill a hole defining how far you want to cut into the cymbal. Afterwards cut towards that whole using an angle grinder. Make sure to file the edges in order to end up with rounded shapes instead of sharp edges.
When you are satisfied with the rough shape, use some sanding sponges to smoothen all the edges.
You will be surprised how small the change in sound is, even if you have to cut out quite a lot of material.
Now go ahead end check if you can repair your damaged cymbals in the same way!