From what I remember about my 1991 570/DP, that mechanism moves with the drive tilt arm, so tilting up/down has no effect if the actual mechanism is physically intact. It is designed to let go if the drive is hit down low. There is a trick to resetting it if it has been tripped and did not re-latch, I apologize for not having the methods handy.
Hopefully others will add to this, or shoot me down, good luck!
