I have a 6 line prostar 816 plus, installed about 6 years ago. This week we had a power outage because of a fire at a local station. 5 of 6 lines will not ring with an incoming call, lines seem to work fine otherwise. I tried taking the one phone that still rings to another jack ....it stops ringing. Seems to be an issue with the main box, checked two fuses one on the outside of the panel, one on the lower board both were good. Other than the ring issue everything seems to function well.

I tried AC off for 3-4 min and reset without any change.

Any help troubleshooting this is appreciated.