First have a look at the SCOBY. If there are black or green patches on it, then the kombucha is most likely affected by mold and should be discarded. Then look, if there are any insects, weevil or pests in the kombucha. If they are 1-2, you could probably discard the impacted portion. If there are too many, then you may have to procure a fresh mother. Smell the kombucha. If it smells pleasant then you are probably OK. If it smells rotten or sewage like, then discard. Trust your senses. Taste a spoon full. It should taste tart and yet refreshing.
In short, if the kombucha that you made looks OK, smells ok and tastes ok, then it is OK.