Stairs not coming out at arrival

[msair]

Hi
Stairs work before departure - can open door and release stairs.
Then departing for a flight. On arrival and door open, the stairs button does not work anymore.
Is there any condition for the stairs to work?
(P3D5.1hf1, v1.03, 146-100)
Thank you
Greetings
msair

[ConcordeAG]

Hydraulics set as described in the manual?

[msair]

hi concordeAG
just tried different settings for yel hyd.
only works for me with eng2 running (stair up and down).
If I understand the manual correctly, deployment should work with gravity only - without hyd. pressure.
greetings
msair

[msair]

I found my fault: AC bus tie on makes the magic happen (= hyd press goes up from 2.5 to 3 psi and stairs work)