Pentax SV shutter overhaul

[Koolzakukumba]

I've got a few old Pentaxes including two SVs and an S1a that all have much the same shutter fault. Basically, the second curtain isn't completing its journey on speeds slower than 1/125th. I haven't got the spare cash to have them serviced and was wondering if there might a DIY fix I could attempt.

I've tred the service manuals but they assume the user has quite a lot of knowledge/experience. I suppose I'm hoping that someone might be able to say where I might apply miniscule quantities of a light oil to get things running again.

 

[ronnies]

I had a similar problem with a Spotmatic F where the second curtain wasn't closing 'hard' enough to kick the mirror into coming down again.

I remember finding instructions somewhere on line that showed where to drip some lighter fluid under the mirror box (with the baseplate off). There was a gear that turned and hit a lever but it wasn't hitting it hard enough. Some fluid on the axle of that gear fixed my Spotty. Drip the fluid in and wind a fire a few times and it will come good again. (or at least mine did)

Ronnie

 

[Jack Conrad]

I'd remove the bottom plate. I think the shutters are constructed similar to the screw mount rf's. Drip a little LF under the slow shutter cog/ratchet thing. And see what happens.
It probably won't help, but you never know.

 

[Koolzakukumba]

Thanks, guys. I'll take a look at that.

 

[Landshark]

The lighter fluid may work but if it doesn't there are two worm drive adjusters on the bottom of the camera. The one toward the back of the camera is the closing curtain.
loosen the set screw and slightly increase the tension.
just adjust a little bit at a time & check the operation as you go.

IF you had a tester that would read travel time, you would adjust both curtains to the same value, then adjust the speeds using the adj points under the top cover.
If they are too far out of adjustment the exposure across the negative will be uneven.