I wish that was the case but apart from removing and testing all fuses I also swapped out the rectifier board from my Flash Gordon and that didn't fix it either.

I have to eat my words here. I just turned on my Flash Gordon for the first time since I had the rectifier board in Xenon and F5 was blown so I looked at the fuse in Xenon again and its dead! I even have a witness who watched me test it on the weekend so don't know why it buzzed out on me then. Anyway by removing J1, J2 and J3 from the rectifier board I've narrowed it down to the cabinet (J2)