Bronica ETRSi repair/adjustment help please

I have a Bronica ETRSi system I use a lot. 2 bodies, 8 lenses, assorted other stuff. Never any issues with any of it. I recently purchased my 9th lens, a 150mm f3.5 MC, and am having intermittent problems with it. It will work fine through a few shots then fails to fire the shutter. When this happens the camera body doesn't cycle through the firing sequence either and it happens with or without a battery installed. With battery it can happen at any set shutter speed. This happens on either of my two bodies, and none of the other lenses have this or any other issue.

I've been doing some diagnosing and have determined that the problem is (or at least seems to be) that the lens isn't fully cocking before having a problem. On one of my bodies, when the shutter fails to fire, if I keep holding down the shutter button and move the crank forward a bit it will cause the shutter to fire. It feels and looks like it is completing that last bit of cocking the shutter which then fires as it should. The other body acts the same but it's not as easy to complete the cocking motion to allow the shutter to fire. The amount of movement required to get the shutter to fire on either body is very very small.

I can see no differences between the bodies or the 150mm lens and any of my others.

So I'm wondering if there is an adjustment in either the body or the lens that would perhaps help. Something that adjusts the shutter cocking limits or distances? Anyone have any ideas?

Thanks much!

Sounds like the shutter is due a CLA. It may be an alignment to camera body or cocking gear wear.

I suppose if you don't want to go the CLA route quite yet, you could wrap some tape or slip a thin plastic tube over the cocking lugs on the lens to see if that makes any difference?
If you are going to any additional expense you can always "upgrade" to a PE lens instead...

If it only happens with this one lens and if it happens with every body then it is the lens at fault, if it happens with all lenses on one body then get the body serviced, if it is with all bodys then I would suspect the bodys, Had something similer with my ertsi a soon after I bought it new, luckily it was sorted out under warrenty, turned out it was a ring in the body that was failing, working sometimes, not others, on all lenses, so check all lenses on all bodys, then get it checked out, could be something as simple as the lens contacts need cleaning, could be something deeper in the lens, fault with the shutter in the lens, if it turns out to be only the one lens then try cleaning the contacts, I had that happen with a 50mm lens last year, cleaned the contacts with methalated sprit and it worked fine
Richard

choiliefan said:

I suppose if you don't want to go the CLA route quite yet, you could wrap some tape or slip a thin plastic tube over the cocking lugs on the lens to see if that makes any difference?
If you are going to any additional expense you can always "upgrade" to a PE lens instead...

Click to expand...

We think alike... I did try a short piece of heat shrink tubing on the cocking lug. This was inconclusive, the lens worked for a few shots and then quit. Looking at the lug the heat shrink had quickly worn through so it may have been better, or not. I am curious if my diagnosis is accurate so I will probably look for some brass tubing to put over the lug. In the mean time I may just pick up another lens. I have a portrait project coming up with my daughter and would like a good reliable 150mm to go along with the 135mm I already have. I've worked on a number of other cameras and lenses over the years but never a Bronica so I may just keep this lens as a test subject. I found a good writeup on the lens' disassembly and it doesn't look horribly difficult.

I have very little experience with Seiko shutters. My experience is with Wollensak shutters, Graphic 1000, Compur all versions for large format cameras. Some of these shutters are used in medium format cameras as well.
Butkus has a ETRSi body service manual http://www.cameramanuals.org/bronica/bronica_etrsi_repair_manual.pdf
Googling for Seiko #0 shutter repair manual turned up http://www.buonaluce.com/Anatomy.pdf . Changing repair to service brought up http://www.buonaluce.com/Tester.pdf as well.

Dust, micro fine metal from normal operation builds up in the lubrication in shutters and the lubrication dries out with age resulting in sluggish moving parts. In mechanical shutters when the speeds start slowing down its a indication of needing a CLA. I have encountered shutters whose times were OK but they would not cock reliably due to the gunk build up (Synchro Compur with mechanisms similar to those shown in the linked repair info on the shutter).

Take good pictures as you disassemble the lens and shutter as they will be valuable for reassembly.

Somewhere on the web there is a video showing complete dissassembly of the MC 150mm lens.
May be on Vimeo...? Anyway, I can't find it now but I once used it for taking apart a messed up 40mm MC lens which I screwed the lens cells into a standard Copal shutter for use on a Century Graphic.
We super-geniuses need to stick together but it does sound like your lens is ready for a CLA.

choiliefan said:

I suppose if you don't want to go the CLA route quite yet, you could wrap some tape or slip a thin plastic tube over the cocking lugs on the lens to see if that makes any difference?
If you are going to any additional expense you can always "upgrade" to a PE lens instead...

Click to expand...

Thanks, I'll start searching. Bronica related repair information is in relatively short supply it seems. I already have the .pdf's referenced by Shutterfinger (excellent) and the factory service manual but that's all I've ever been able to find. If I can locate the video you mentioned I'll post a link in this thread.

Googled Bronica lens disassembly and the first two links are: http://www.buonaluce.com/Slens.pdf and http://www.buonaluce.com/PSlens.pdf and some videos which should be of help.

http://www.buonaluce.com/Slens.pdf
Maybe helpful (though it's about the disassembly of a ZENZA BRONICA ZENZANON 150/3.5 S Lens for SQ series) but the author says the information should be valid for all E, MC & S lenses.

EDIT : shutterfinger was quicker ... Sorry!

Thanks guys! The bounaluce site is probably the best Bronica repair source on the web. Fantastic detail about the Seiko shutters in there, and yes I expect the S lens information should be close enough for the MC. And thanks too Shutterfinger for the video. I'd searched Youtube already but hadn't found that one.

Wow, that's terrific!