Bronica SQ-A 120 back comes open by accident... won't stay closed.... help please

[r-mm]

Hello All

I recently bought a Bronica SQ-A and have a problem with the 120 back that I can't find anything on by searching. The back doesn't close very well. To get the two locking tabs to grab their latches I need to press down on them while closing (ie exert pressure on the back door of the back near the ISO dial while pushing it shut). The corollary of this is that if I exert some upward pressure on the back, say by accident or in a camera bag, the latches will release and the back opens. The only obvious mechanical flaw I can find is that the little plastic tabs that guide the back magazine into the back have cracked. They are the pieces located where my fingers are pointing in this image: https://www.flickr.com/photos/r-mm/14069250816/

I can't quite wrap my head around why those would be causing my problem. Can some one tell me if the back is suppose to "snap" closed on its latches when NO magazine is installed? Because mine does not. I also noted that when closing the back with the magazine in place, it wants to bind up on the top of the magazine and I need to coax it to clear it.

Is my whole back just off kilter? I suppose the easiest path forward is a new back, but i'd like to understand the nature of the failure on mine first.

Thanks for your tips all.

 

[DWThomas]

Hmm - I just pulled one of my SQ-A backs out and the back shell/cover/door clicks into place smartly with no insert installed. I too don't see why those little flanges broken off should affect the back latching. I think they are more likely a sort of labyrinth light seal for those weird corners, in which case you might get some light leakage. I also don't see any likelihood of upward pressure on the door popping it open on mine. Is the hinge at the opposite end of the door relatively tight and free of sloppy motion? I really don't see how the latches could unlatch from any motion the actual back shell could make, assuming the back isn't damaged.

Strictly a guess, but I might wonder if the back had been dropped -- better yet, a whole camera dropped landing on the back -- and bent something seriously out of kilter. Working, they're great cameras, but there are a lot of little complexities in the system.

Good luck with it -- and welcome to APUG!

 

[Alex Muir]

The insert has to be seated properly for the back to close. I find that I sometimes have to move the insert around a bit to find the correct location to allow the back to close. If it pops open, it sounds like the latch mech has not fully engaged. I will look at mine later, but I had thought the latches operated horizontally, and upward pressure would not affect them. Are the two pieces you press to open it moving fully back and forth? Perhaps they are sticking, or their springs are weak.
Alex

 

[r-mm]

Thanks for checking guys. I spent a lot of time looking at the assembly last night and figured the only way this could be happening is if the relationship between the male and female parts of the latch was askew. The female part is held tight in place and clearly intended to stay where it is, and the "door" of the back was catching, so I gave it a bit of corrective bending with my thumbs and lo the problem seems to have gone away. Latches right with no magazine and no upward pressure will release it! Let's see if it hold fast. Hope so since I'm about to run my first roll of non expired Portra thru it.

 

[Alex Muir]

Glad you got it fixed. Last week I opened mine by accident when I meant to remove it from the camera. Operator error rather than a mechanical fault.
Fogged most of the roll!
Alex

 

[DWThomas]

That sounds promising, I hope it works out for you. As Alex says, sometimes a little teasing is necessary to seat the insert. I might wonder if those broken off ribs on yours are from some gorilla attempting to slam the door shut instead of re-seating the insert first.

My original Bronica intent was to go minimalist, a body, a back, WLF and 80mm lens, with some thought that a second back might be handy. I've now, after 7 or 8 years, got about 2 1/2 camera's worth of stuff, partly because it can be handy to have two different setups ready to roll, but it's also nice to have extra components to switch around if trying to isolate a problem. Other than something weird in my original body, the backs seem the most trouble prone. Although the most common problem is degraded light seals which can be DIY repairs.

I also have been pleased with what I've been able to do with my SQ-A, so that tended to loosen up my spending habits. (Just bought a longer lens and a 2x telextender in the past year after wishing I had one in the midst of a project. It boggles what's left of my mind to see what the stuff sells for today versus back when it was current production (in which case I wouldn't likely own it!)