Specialized brain in Rockshox SID

I have an old SID with the brain function.

My understanding is that when the vlue dial is turned to the softest then the fork should perform almost as a normal fork with no brain function. However it's still really hard to push through even when turned right down.

Turning it to it's hardest makes little difference?

Anyone have any experience?
Can tye brain units be serviced to be less firm or is there something going wrong and it won't turn off properly, Ideas?

Many thanks

Matt