Mora's Jewelers is one of the few businesses I know which is almost entirely dedicated to jewelry repair. Better yet, it's located only a few blocks from where I live. It's a very small location owned by a mother and daughter. They have a small selection of jewelry but the bulk of the business is repairs. They are constantly busy. On the one occasion that I visited to get an estimate and drop off an earring and ring to be repaired, in the middle of a weekday, mind you, about 5 customers dropped off jewelry and watches. Moira looked at my ring and repaired it on the spot at no charge. The earrings were repaired, cleaned and sparkling the day before they said they would be ready.
One drawback to the store is that if there's a family emergency/event, they may close the store early without warning since it's only the mother and daughter that work there.