Pentax 67 Shutter Issues

I've been having issues with the shutter times on my Pentax 67. I first noticed the problem during a night shoot that required bulb (B) exposures. The shutter wouldn't stay open and shut after what felt like 1 second. Now, after dry firing the camera a few dozen times I've realized the problem is more severe since all shutter times will only work correctly sometimes but usually default to something that feels and sounds like a 500th or 1000th. Long shutter times like 1/4, 1/2 or 1 second work sometimes but are usually way too short.

Has anyone had this problem? Is it possibly a weak battery or will it require expensive repairs?

thanks,
Max

These are large shutters and do need maintenance from time to time. Probably a service would be a good idea?

It's funny as my friend had a similar problem with his 67. In the end he got it serviced. Not cheap, but worth it. Now? He is delighted that he has got his 67 back. It's like a new camera for him.

Probably not what you wanted to hear, but like John has said, they are worth getting a service every so often.