My fuse "looked" good but I got a new one and all lights, displays now work. Had an electrician over for other job, and he tested 2 that were hard to tell visually, but they were both bad. Going to grab a few to have on hand ( I believe they are 20 amp mini fuses). I went through all of this with my first Hayward aquarite, replaced the thermistor and got another few months out of it before it quit on me again. So I replaced the whole control box. Now I'm wondering if it was the fuse all along.