Bronica ETR Lens only shoots at mechanical speed

[Yobo57]

Hello, I recently picked up a Bronica 75mm that almost only ever fires at the mechanical 1/500s. Cleaning the contacts did not help and I noticed they were a bit worn looking.
Can this damage be enough to account for the malfunctioning? Is there anything I can do to get it to work again?
I have another lens and it fires fine at all speeds, so it’s not the body the issue. I’ve included photos of the contacts as well as the contacts on my other lens for reference of what undamaged looks like.

 

[abruzzi]

Since they run at mechanical speed when the camera's battery is dead, I assume you eliminated that possibility? Do you have another lens that works normally?

I'd take a pencil eraser on and around the pins on the lens, but also the contacts on the camera body. Then finish it off with isopropyl alcohol. It seems unlikely but I suppose that could reduce the power getting through causing the shutter to not pause between open and closing strokes.

 

[Yobo57]

Since they run at mechanical speed when the camera's battery is dead, I assume you eliminated that possibility? Do you have another lens that works normally?

I'd take a pencil eraser on and around the pins on the lens, but also the contacts on the camera body. Then finish it off with isopropyl alcohol. It seems unlikely but I suppose that could reduce the power getting through causing the shutter to not pause between open and closing strokes.

Yes, my other lens works perfectly fine at all speeds. I’ll try the eraser out, I tried isopropyl alcohol earlier but it didn’t help unfortunately.

 

[abruzzi]

Unfortunately I have a 80mm for my SQ-A that had a similar problem, but more intermittent. I ended up just replacing it. Fortunately the lenses aren't too crazy expensive (try shopping for a Rollei 6006 lens!) but they have gone up in price. I fortunately outfitted my ETRSi about 10 years ago when lenses were ETRSi and Mamiya 645 lenses were bargain priced, and a lot of school were dumping collections of Bronicas and you could get a 75mm for US$75. Those days are long gone.

 

[koraks]

With the SQA lenses I know that there's a solenoid that controls the shutter, and it's fairly common that the solenoid itself or something related to it malfunctions.

 

[Don_ih]

There may be a loose connection inside the lens. Those pins look oddly chewed up - I have no idea what could cause that.