Bronica ETRS Zenza Bronica Zenzanon EII 75mm Disassembly

[CaCtus_SaNdwich]

Hi, I'm attempting to service a Bronica 75mm lens due to a sticking shutter.

I've hit a wall while trying to remove the shutter to clean, on the disassembly guides I've been using it says to use a wrench to unscrew the lens lamp ring, mine is not budging one bit. Am I missing something? There are two screws that appear to be blocking the ring, which don't seem to want to move either, but they aren’t shown being removed in both pdfs.

According to the service manual, it's just a case of unscrewing. I've attached the PDFs I'm using, along with a photo. Any advice would be greatly appreciated.

Cheers

 

[OAPOli]

The retaining ring should unscrew. It's possible there is some adhesive; try wicking some solvent but be careful with acetone as it can scar plastic. I've taken two of those apart and one had a super tight rear lens group.

The two screws are on the shutter side and are meant to locate the shutter.

 

[CaCtus_SaNdwich]

The retaining ring should unscrew. It's possible there is some adhesive; try wicking some solvent but be careful with acetone as it can scar plastic. I've taken two of those apart and one had a super tight rear lens group.

The two screws are on the shutter side and are meant to locate the shutter.

Thanks for the reply, I'll give it a bit more umff and try use some solvent to help. I'm trying to get down to the shutter blades to give the pivots a clean as it is sticking open. Judging from M.Vettore Anatomy of a Seiko #0 shutter it looks like they are accessed from the back by unscrewing the 4 screws on the brass retaining ring, is this something you have any knowledge of?

Cheers

 

[OAPOli]

I haven't been inside the shutter. I believe the screws to split the aperture block from the shutter block are under the black ring in the photo. This ring is removed via the four screws on the brass ring.

Usually one has to check at the front of the shutter for any springs resting against the casing. Otherwise those can be damaged when the casing is reinstalled. But given this is an electronic shutter I'm not sure if that is necessary.