If you checked the fuse visually, you should also check it with an multimeter.

I personally think the best way to check it is to see is the hour meter working on the service panel. When the fuse is OK, the working hours should be displayed.

I'm telling you this because every single WAVE I've worked on had a faulty fuse housing. Usually the operators break the little metal pins on housing cap so the housing can not be closed properly and establish a good contact.

Regards!