I tried to install an ALG AK trigger in my Arsenal 107F last night and got through most of it by watching some videos on youtube and reading the instructions but the trigger doesn't work.  When the hooked part of the disconnector is fully engaged with the shelf on the hammer and I pull the trigger nothing happens.  If the disconnector is not fully engaged then when I pull the trigger the hammer releases.  I reinstalled the disconnector several times to make sure the spring was in there correctly and it has a little bit of spring tension but not much travel when the trigger is stuck and won't release the hammer.

I may be getting some of my terminology wrong but here are some videos I made to show what's happening.  The first video shows when the trigger is stuck and the second shows when it releases.

https://www.youtube.com/watch?v=4ScscRwkP6s

https://www.youtube.com/watch?v=KzZmtCYkoPI

Any help is appreciated!

The vid is too short to be able to see what’s going on, but it may be the safety roll pin being setup wrong.

There are some known issues with the AKT and Aresenals. Is there interference between the disconnector tail and the rivet? In Arsenals that rivet can be a little on the large side and cause issues. The fix is filing down the rivet if there's contact.

I wouldn't think it has anything to do with the safety roll pin since the safety is completely removed in those videos.  When you rack the charging handle back the disconnector catches the hammer.  When I pull the trigger the disconnector is not releasing the hammer.

Here's a slightly longer video showing if I only lightly engage the hammer/disconnector when I pull the trigger it releases but if I fully engage it then it's stuck.

https://www.youtube.com/watch?v=R4O_irQZQeE

I'm not seeing any contact between the rivet which is a flat not a domed rivet.  It's possible it's contacting the tail, I may have to cut off the tail of the disconnector

You posted a 4sec video, there’s not much of anything to see in that.

Did you look at the second link?  It's a 22 second video.

https://www.youtube.com/watch?v=R4O_irQZQeE

Tried to embed that, didn't work.  dryflash

I reinstalled the FGC and now when I cycle the charging handle and pull the trigger and left off before I charge the gun again it cycles properly.  If I leave my finger on the trigger and charge it then let it out for a reset it does not reset.  I have to manually push the back of the trigger towards the muzzle end to get it to reset.

Your disco is bumping a rivet. If you actually read the install instructions that came with the trigger they detail this known issue.

Those rivets in Arsenals are too tall.
RobSki cuts the tail off of the ALG disconnector, so I did too.
Works fine.
In another, I used a Tapco G2 disconnector and cut (shortened) the tube that goes inside over the trigger pin. Works fine. Had to try it after seeing a YouTube on it. This school of thought was that the G2 disconnector was meatier and a stronger part which had no tail to impact on the rivet.

It wasn’t the rivets the hammer spring had to be bent

Awesome. Glad you got it fixed. How'd you get it figured out?

Called ALG customer service they were great