Repairing RZ67 film backs

[Rudeofus]

Two of my RZ67 film backs (120 film backs, one is pro, the other one a pro ii) have given me trouble lately. One fails to tell the camera that the dark slide has been removed, so the camera won't fire even if everything is set up correctly. The other back got stuck with film inside and won't advance to the eighth frame, even after applying moderate force (short of breaking it or ripping the film inside). I have some mechanical skills but can't really spend weeks on these parts.

Is it possible to repair these film backs with little effort or are they little mechanical wonders which take weeks to fix and days to reassemble? Is it likely that something is just stuck or did something inside break which I can't replace anyway? Does anybody know of online instructions how to disassemble these film backs? How easy is it to at least get the partially exposed film out safely (i.e. so I can still develop it and enjoy the pics)?

 

[Kevin Kehler]

For the film in the camera, in the dark, you can open the back and wind the film on the spool; you lose 2 shots but better than ruining a roll. Might be a kink in the film or something has jumped the track, no way of knowing without putting more film through it.

As to the fails-to-shoot, one of my backs does that. If I rotate mine into the portrait position, it fires but refuses to shoot in landscape position. I took one apart once, there is some electrical wiring and circuits inside. I didn't want to send it away (cheaper to buy a used one) and just have it labeled so I know to use it only in portrait positions.

 

[codex0]

At one point I had a dead back that I took apart to see what made it tick - it was fairly complicated, and difficult to get open. I don't remember the dark slide section of the mechanism being complex - it might just be a spring that has fallen out of place in your case.

 

[2F/2F]

Especially with the electronic backs of the RZ, as opposed to the RB, I think it is worth it to have them professionally serviced if they are giving you trouble. They should last you a very long time if they are well maintained. Servicing backs is just something you have to do every once in a while.

 

[nick mulder]

They are a bitch - there is at least one reverse thread...

I managed to fix one of mine once, but it broke again a year later and I've given up on it

 

[TimmyMac]

I've fixed a jammed one, but don't ask me how to do it again. I get my RZ backs from KEH as-is and refoam them.

If you're handy with a small screwdriver and have good eyesight, it shouldn't be too much of a problem. It depends on your experience with these things. Anyways, the cost of getting one serviced will likely be more than the cost of a replacement from eBay or KEH, so have at it.

 

[Rudeofus]

Here is a lengthy update to my film back thread:

I went to my photo clubs dark room and took out the films - which fortunately wasn't a hassle. The film in the pro ii film back was clogged - I took it out and hope the next film will be fine. I remember that I may have made some errors when I loaded the film.

About the older magazine which wouldn't let the camera fire: I took it apart and learned some interesting things. Unlike what was stated above, there are virtually no electronics inside besides a complicated switch for the ISO dial. If one doesn't use the AE prism, chances are that no electronics are involved in taking a shot as far as the film back is concerned. All functions (reporting that a film is loaded and advanced to the next frame, that the dark slide has been removed) are communicated mechanically through multiple levers and a small rod.

It was quite simple to disassemble the frame part of the film back, only tool required was a small watch makers phillips head screw driver, some patience and a good memory as the screws all have the same thread but different length.

Unfortunately I was not able to disassemble the insert (which holds the film spools). The phillips head screws came off easily, the bottom came off easily, but the more interesting top part won't come off. Something holds the film transport knob in place and it won't come off with the tools I have available.

For all those attempting to trouble shoot RZ67 film backs: Whether there is a dark slide inserted or not is communicated by a lever at the bottom of the frame part of the film back (right next to the lever which locks the back to the camera body). Whether there is film loaded or not is communicated through the insert: there is a rod inside the film advance gear going to the camera which does this. If your camera says you have the dark slide inserted although it's removed (red battery check LED is on), you only have to look at the frame part. If the camera says there is no film loaded or that it hasn't been advanced to the next frame (orange advance lever LED goes on instead of an exposure), you need to look at the film insert part.

As far as my backs are concerned: the pro back seemed to work again (tested with 20 years expired color film ) after reassembly, no idea why it didn't work before. Maybe some spring loaded part got stuck from long non-use. I assume the pro ii back will also work fine if I load the next film correctly

 

[nick mulder]

Unfortunately I was not able to disassemble the insert (which holds the film spools). The phillips head screws came off easily, the bottom came off easily, but the more interesting top part won't come off. Something holds the film transport knob in place and it won't come off with the tools I have available.

The rubber top pops off - a little gummy bit of glue holds it in there - then under that is your reverse/left handed thread... All the effort you've put in loosening it so far has been fastening it even more