Replacement is needed. You can retract at the control pad, and check which one(s) aren’t retracted. Do reverse, deploy at the control pad, and check which don’t extend. In either case, the faulty ones are no good, and can’t be fixed. There is a slight chance it’s another reason, the bus each of the interceptors plug into, in your bilge, but I’m pretty certain it’s almost always dead interceptors that need to be replaced.
Sent from my iPhone using Tapatalk