If your Holga 120N camera for some reason won’t give you that click when you advance your film it’s probably no big deal to solve it.
This is what I did.
Remove the film advancer knob with a small knife or similar, this one is just glued a little so you won’t have to use much force.
Under this knob there are two small screws, loosen these and the third one that sits on the right hand side of the camera. Now you can remove the top of the Holga.
In my case the small “teeth” on the film advancer knob was worn out so I took a sharp knife and grinded just in front of every “tooth” so the drop would be bigger. I also glued the small copper piece that pushes against the knob.
That’s it! Reverse what you just did and you’re good to go!
Hope this helped!