Trigger wont engage on Asso115

[Mufazalov]

Hi, pneumatic gurus.
I was messing with a trigger on my Asso on dry land and it suddenly felt like it 'fell in'. After that the piston simply goes up and down (when I push it with the shaft @5bar) but doesnt get locked.
I took the trigger out and saw that the pin is just immovable for some reason.

Any suggestions?

I tried pressurizing the gun to 10-12 bar but to no avail

 

[popgun pete]

The coil spring that biases the sear lever may have tipped over and no longer pushes the rear of the sear lever down and hence the sear tooth up. If that happens then the sear tooth cannot catch the piston tail as the tooth stays depressed.