B&G/Simrad AC42N Autopilot Popping fuse

[rspott]

I have a B&G/Simrad AC42N Autopilot Computer that just recently started blowing the 30A blade fuse installed in it.

I disconnected everything from the unit but the supply power and it continues to pop the fuse. I have not made any recent changes to the boat/device to really point to a problem.

Has anyone else had an issue like this?

Does anyone have a used unit they would like to sell to me?

What is the current version of this device if I have to replace it with something modern?

[DeBe]

With only the power conected the only thing i can think of that would blow a 30A fuse, is faulty transistors in the H bridge circuit that drives the steering. There will usualy be 4 of them & it would only take 2 of them to be short circuited.