Pentax MX shutter sticking on Slower Speeds

CaCtus_SaNdwich · 2026-01-28T07:01:41-0500

Hi All

I'm looking for some CLA advice for a Pentax MX I've picked up.

The shutter is sticking on slower speeds 1/30th - B and doesn't budge at all, keeping the curtain open and the mirror up only when turned to a speed over 1/30th and re-cocked the shutter closes and the mirror drops down.

I've taken the bottom off to have a look and from I can see the slow shutter assembly seems to be jammed and is holding the shutter open.

I've attached a photo, part B which I've marked I'm guessing adds some resistance to part A to get the desired shutter speed.

Any suggestions of points to clean / re-lubricate would be appreciated, I've attached another photo to annotate points.

Many Thanks

dynachrome · 2026-01-28T19:39:04-0500

I would send the camera to Eric Hendrickson. If my memory is correct on this, the MX came out in 1977. That's a long time ago. I have at least three MX cameras. They are generally reliable but do need service sometimes. The weak point is that the LEDs get dimmer over time. I don't know if there is a cure for that. My KM cameras have probably seen more use. I have not had much luck using different focusing screens with the MX. Since I don't have an LX, if I want to use different focusing screens, I am more likely to use a Canon F-1 or a Nikon F2. With what film costs today, if I know I will want to use a camera with any frequency, I would rather get it serviced by a good repairman person.

runswithsizzers · 2026-01-28T20:08:52-0500

dynachrome said:
I would send the camera to Eric Hendrickson. If my memory is correct on this, the MX came out in 1977. That's a long time ago. I have at least three MX cameras. They are generally reliable but do need service sometimes. The weak point is that the LEDs get dimmer over time. I don't know if there is a cure for that. My KM cameras have probably seen more use. I have not had much luck using different focusing screens with the MX. Since I don't have an LX, if I want to use different focusing screens, I am more likely to use a Canon F-1 or a Nikon F2. With what film costs today, if I know I will want to use a camera with any frequency, I would rather get it serviced by a good repairman person.

That is very good advice for Pentax MX owners in the USA, but acording to his website, I'm afraid Eric Hendrickson does not accept international repairs:

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Pentax MX shutter sticking on Slower Speeds

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