Raymarine i60 Masthead unit

[NigelFortune]

I have some issues with the above unit. Checking the voltage coming back on the 5 pin plug I’m getting a change in voltage coming back on the speed signal but on direction signal both cos and sin are static when I rotate the vane. I need to get into the unit to further fault find however I’m finding it difficult to see how the top comes off. When I take the vane off there are 4 counter sunk screw holes in the top of the unit with no screws in them. Looking at You tube videos they show screws in them. I’m considering maybe the top is threaded onto the base or even glued together.
Has anybody gone this far ? I don’t want damage it . Ideas please.

Thanks
Nigel

 

[[164147]]

There is a single screw each holding the vane and cups on. The top half of the dome simply unscrews.

 

[[164147]]

The vane signal comes from a hall sensor:

https://gmw.com/wp-content/uploads/...tkgjQVyBgJWybFkafLdrDN0iIEi9iLu5JRvHFbqiQexIA