Bronica SQ 120 Back not advancing film

[sygyzy]

Hi,

I am not super familiar with MF or Bronica's, though I am learning. I have a particular Bronica SQ 120 back that does not advance film. I actually gave up on trying to fiddle with it a while ago but I want to focus my attention on it again. I just remember when I had film in it, it wouldn't advance the film, but I don't recall the specifics.

What is the easiest way I can test for this, hopefully without loading any live film? Could I simple put the back on the camera and take a shot (without film) and wind the crank? I should see the counter on the film back advance (0 to 1), right? If it doesn't, what might be the culprit? Would it be better to get a new (used) back on eBay or KEH or get it repaired? Finally, would the mechanism that likely failed be located in the insert or the shell? KEH has inserts for about half what an entire back would cost.

Thank you for your help, I really appreciate it.

 

[gone]

If it's like other cameras, I don't know how you would test it w/o running film through it. You may have to sacrifice a roll for that purpose.

 

[RedSun]

Bronica makes good gears. I've not seen a back with broken gears. Very likely that you did not load the film correctly.

To test it, cut a piece of paper from the grocery bag (brown paper). Tape it to the roll film spool. Load it. Attach the film back to the camera, but do not close the back. Wind the film with the camera winding lever. If you see the spool moving, then it is fine. You can also close the film back and wind the brown paper film. Then you should see the counter advancing.

For all the above, the multi-exposure lever is in normal (upright) position....

 

[DWThomas]

If you develop your own film -- or maybe from a local lab -- all you need is the backing paper and a 120 spool to simulate the film close enough to check these things. Is the multi-exposure lever off? If on, the film does not advance. (I ask that because it's common to turn on multi-exposure to allow firing the shutter without film installed.) The counter does not run unless there is quasi-film installed. In fact, one occasional back failure mode involves the film going all the way through without stopping and without the counter moving -- but the film ends up on the take-up spool.

 

[pdmk]

I shot on Bronica only once or twice, but I think it should be not so different from other MF cameras.

1. Is the crank moving?
2. when you move the crank can you hear spool rotating in back? (counter would probably not change without film)
3. maybe stupid but check if you camera is not set on M - multi exposure mode, which doesnt move your film