Pentax Auto 110 Can’t See Through Viewfinder/ potential Stuck Shutter

I just acquired a Pentax Auto 110 SLR with 2 lenses, auto-wonder, case, and a couple of rolls of film. When I got it, I could not see through the viewfinder, the film advance lever would move about halfway, and it seemed like the shutter was stuck.

 

I just bought a pair of brand new Energizer 357/303 1.55v batteries and put an old roll of half-used 110 film that was in the camera.

 

A solid yellow light shows up in the viewfinder, but nothing happens when I press the shutter button, also, nothing happens when I try to cock the film advance lever. I still cannot see through the viewfinder.

 

Is this a known problem? How can I fix this really neat camera?

The Pentax 110 body has a two-bladed combined shutter/aperture mechanism, in front of the reflex mirror. When viewing, the shutter/aperture is normally open, and the mirror down, which also seals the film compartment. You can see this if you remove the lens, and if you remove the back, you should see the mirror in the down position.

 

It's possible the camera was fired with weak batteries, and froze mid-cycle. Sometimes old electronic cameras can take a while to come back to life if they haven't been used in years. Try it again periodically over the next day or two. The Auto 110 Super version, which is less common, has a shutter lock feature as well.

 

Also, you may want to see this old thread:

Pentax Auto 110 Shutter Will Not Advance

Edited May 29, 2021 by m42dave

The manual also specifies silver-oxide batteries for best performance. Some electronic shutters are rather sensitive to insufficient voltage.

Ok, so after reading the manual and learning about the parts of the camera, what seems to be the problem is that the aperture diaphragm is shut (or stopped) all the down.

 

There is no light being let through the aperture diaphragm. Therefore I cannot see anything through the viewfinder.

Sounds like it seized up mid-cycle, then. If the shutter diaphragm looks clean (no obvious oil) and it doesn't come back to life with fresh batteries, then it could be due to a number of issues (dried-up lubrication, shutter magnet, capacitor, etc.). Given that these little cameras are now around 40 years old, nothing would be surprising, and unfortunately not cost-effective to get repaired. Learncamerarepair.com does have a service manual available if you want to look into this yourself:

 

Product Details | Pentax Auto 110 Repair Article | Pentax | Service Manuals | Learn Camera Repair

Edited May 29, 2021 by m42dave