Pentax mirror locked up...How to fix

[gb hill]

My stepson has a Pentax Spotmatic that hasn't been used in years. The camera is clean, lightseals good but the mirror is locked up. Any ideas on how to fix. Needs a battery also what should I get. I would like to try this little camera out.

[Kim Coxon]

Open the back and check the shutter operation. The most likely culprit especially as the camera has not been used for some time, is the the second curtain is not travelling fully. This means that that the mirror is not being released. Does the mirror come back down when you cock the shutter? Exercising it may help but you would be better off getting a CLA done. If you need a suggestion in the US for someone to do this I will send.

As to the meter, the good news is that Pentax was one of the very few makers who used a balanced bridge circuit. This makes it largely independant of battery voltage and the meter will be as accurate with a silver cell as a mercury one. You can get the right shaped silver cell but an ordinary button cell the same size works just as well. I will check the number this evening at home.

Kim

[gb hill]

The shutter looks good at all speeds and closes fully. No the mirror is stuck in the up position even when cocking the shutter. I also have your pentax manuels and may take off the bottom plate and see if anything is broken or jammed. Thanks for your help.

[greyhoundman]

Check the foam bumper strip for the mirror. They get like glue and will hold the mirror up.

[patrickhh]

Originally Posted by greyhoundman

Check the foam bumper strip for the mirror. They get like glue and will hold the mirror up.

Seconded. I had that problem once with a MX (shutter working, but mirror sticking)
Good news is that it is cheap to have the foam replaced, some people even fix it themselves.

[Murray Kelly]

The Pentax Spotmatic I passed on to my son had that problem. Initially intermittent but gradually more and more common.
It seemed to be related to the iris preview latch. That is, the lever one pushes up to preview the DoF. Eventually it didn't even need pushing up to stick. It was a pointer, tho.
I looked closely at the repair manual in the 'net and from the exploded view I was left wondering if the little lever that the mirror strikes as it flicks up as it closes wasn't clearing the mirror and catching it semi-permanently, so to speak. This lever resets the diaphragm to wide open ready for its close -> open sequence during exposure. It then should get out of the way. It wasn't.
Long story short - I took an oiler can with a 'very' fine applicator and without dismantling the camera, placed one drop of oil in this lever hole and laid it on its side so it would run to the left (from the back) and into the region mentioned. It worked.
You can just see this little projection if you look carefully into the mirror space high up on the side. The matt black doesn't help, but with persistence it is visible.
I am not saying it will work for you, but that was my experience.
Hope this helps.


Murray
Brisbane, Oz

[titrisol]

BATTERY: A 385 battery works great, as Kim said the Spottie can use silver batteries

STUCK MIRROR: a good CLA will not hurt the camera and will provide many years of use, chek pentaxrepairs.com

[charjohncarter]

The 385 just drops in. And this guy does a great job. I think it was $98 for CLA and repair of meter (which yours could need, this is a common problem):

http://pentaxs.com/index.html

[Kim Coxon]

Erik is highly thought of on most of the Pentax forums and is generally considered to be to Pentax's what Sherry and DAG are to Leicas.

Kim

[charjohncarter]

One other battery question that comes up. The original Mercury 675 had 1.3 volts and the 385 has 1.4-1.5 volts. Everybody wonders if you then get incorrect readings, you don't. Pentax used a bridge circuit which equalizes the juice to the needle in the viewfinder. If you used this battery in a Olympus Trip 35 you would get an incorrect reading (you have to used the hearing aid batteries in most small 35 cameras from the 60-70s). If your meter reading is slow and it produces overexposed images send it to Erik.

[gb hill]

I cheched the mirror again and it's not stuck by glue. I don't want to force it down too hard, but it does have some resistance like its hung. I think i'll try Murrys idea and see if it works. If not I will see about sending it off to Eric. Thanks for the help and the link.