Bronica ETR - 120 back film advancing issue

Hi all

OK so I have this new (to me) Bronica ETR and put it together with some pieces from KEH in December with some other parts. I though every thing seemed good but so far not managed to use it due to this issue below.

I put the film in the camera back as one should and lined up the arrows with the red line inside, this worked great. I then managed to wind the film from S to 1 that worked great, I then took a photo but when I went to advance it the counter didn't move from one, any idea whats wrong.

In multi exposure mode I see it moving the 120 back lever from the body of the ETR when turned there but I just can't get it to advance the film, what could be the problem and what can be done to fix it do you think?

Any help for this total newbie who is desperate to get going please do let me know.

Hello

ETR system has plenty of failsafes and is virtually foolproof. Since you got the shutter to fire its first frame, then I trust that you have the dark slide removed and shutter lock released. So let's move on. In order to advance film properly, the camera must "feel" the film back/magazine, for which purpose there's a pin on both - camera and back. I have circled the part on the image below:

When you turn multi-exposure OFF, the film advancing gear extends from the camera to match the corresponding gear on the back. And when you advance the film, the aforementioned pin locks advance mechanism in an appropriate spot to make the second shot. My best guess is that either the pin is bent, or it requires cleaning. It happens sometimes.

You mightn't happen to have a second back, to rule out the body damage?