Logos have a life span. Even a great logo will eventually become aged, and will need to be replaced before it becomes a marketing negatigve. If your logo wasn't all that great to begin with, it's a marketing liability, and that needs to be fixed ASAP.
David E. Carter has been a major force in the logo world for over 35 years. He is the all-time best-selling author on the topic, and has designed more than 300 brand identities all over the USA, and on 5 continents, specialzing in small and mid-sized busineses.
Old logos (and some young ones) need a re-design. There are two options: Change by 1. Evoluition - when your existing logo has erquity, the foundations are retained, but are broughj up to date. 2. Revolution - the logo has many negatives - tear it down and start over. Do it right.
David E. Carter makes old logos better.