Pentax SF1 wont advance film

[fred0000]

When i go to load film, i hear the motor turn, but the drive sprokets for the film do not turn, and i cannot turn them freely, feels jammed? maybe a gear came out of place? any ideas, or does anyone know where i could find some teardown instructions, thanks in advance

 

[compur]

Film advance issues are pretty common with the SF1. It used plastic gears in
the advance mechanism which wear out or break and Pentax no longer
supplies these parts.

I would just get another body -- they don't cost much. You might want to
get the SF1N instead. It's an updated model with a better reputation for
reliability. Or, one of the later models.

 

[Machiavelli]

Film advance issues are pretty common with the SF1. It used plastic gears in
the advance mechanism which wear out or break and Pentax no longer
supplies these parts.

I would just get another body -- they don't cost much. You might want to
get the SF1N instead. It's an updated model with a better reputation for
reliability. Or, one of the later models.

HERE'S THE PROBLEM: look into the mirror cage of the SF1 on the left side there is a tab that moves up and down in a slot. Try moving the tab up and down if it moves very freely with no resistance rather than having resistance to it moving up and then springing back down by itself it means that a spring connected to the lever has broken. The spring is located on the underside of the mirror box near the back hooked to a lever and a stationary fixture of the box. You will propbably find the spring borken in half with one end glued. The solution is simple replacing the spring the rest is not. The original spring is too weak and flimsey it breaks almost in all Pentax SF1 cameras jamming the camera. You will need a like-spring but a bit more robust because it operates every time the shutter triggers. The mirror box needs to be pulled out. The original Pentax service manual only has dissasembly and assembly instructions no trouble shooting section! Get it anyway from butkus.org as pdf file. It's do-able but time consuming and requiers desoldering of some wires and carefull systematic dissasembly a lot of tiny screws! The real issue is finding a like-spring it's very finely wound and small, you might have to improvise a spring from another. A good way to get tiny camera springs is to buy cheap broken mechanical cameras on Ebay and take them apart for parts, springs are often very similar in shape and size or near enough for use. That's what I do for generic spare parts. I replaced this spring in an SF1 that would not advance film and it works as good as new. A pro can do it but will charge about $125-50 to do that's a lot for an old camera. It's the time involved to do the work. I hope this helps.