5a is too low. It's a fast fuse. The game is specced for a 5a slow blow in the switch box, so this is the minimum requirement to prevent fuse blow at switch on. The 5a fast fuse will quickly fatigue as the current in rush is close to max rating. I install 7a plug fuses but they're not easy to buy off the shelf. If with 7a installed you still get blows, then suspect input filter.