Pentax ME (or ME Super) recurring problem

[David Lyga]

I have to ask this because it happens rather frequently when I test these particular Pentax electronic SLRs.

I will attempt to cock the shutter and the curtain rises properly, but the shutter does not end up getting cocked! There is some internal lever, I think, that often does not get turned where it is supposed to go in order to set the shutter. The 'feel' of the film advance lever is normal. The curtains have absolutely no oil or other impediment, and rise normally, and stay in that raised position, as they should, but after advancing film (and when the advancing lever is back at its origination) one can advance the lever again. Never, at any time, is the shutter cocked. Of course, the curtains remain, thus, 'permanently' in the 'cocked shutter' position. The only way that they would return to normal would be if that shutter fired, but, again, it is not cocked.

I have seen this on literally countless ME and ME Super SLRs. There is a common failure here and I have a feeling that the remedy might be simple, because you can almost feel that an internal lever wants to engage. There is absolutely nothing gummy inside the camera holding up the works. This happens just as often with brand new looking bodies, so I think that it is not a question of the SLR being overworked.

Anyone know what is going on here, or is this thread doomed to be unanswered? Thank you. - David Lyga

 

[lxdude]

I've had the same problem, fixed by a repairman. There is a small lever that is bent, as I understand it. I don't recall if it's under the top or bottom cover, but I was told it's a pretty easy fix.

 

[David Lyga]

Thank you, Ixdude, for allowing me to feel sane. Yes, it does happen and disturbingly frequently, What REALLY frustrates me is the fact that even on cameras that look brand new it happens. Maybe someone will be able to zero onto this solution. I will retain hope. Thank you. - David Lyga

 

[PentaxBronica]

Yep, I call it the non-cocking shutter problem. The film advances but the shutter doesn't cock.

Seems to be more common with the ME Super and later M-series bodies, I've yet to have it with an ME.

 

[David Lyga]

Actually, both the ME and Super seem to have the same innards, except, of course, for the manual ability of the Super. The gearing seems to be the same. I KNOW that this solution is going to be given in a coherent way: just the fact that TWO alreadly know of this problem gives me hope. I will persist. Thanks.

SORRY MODERATOR: MAYBE I SHOULD HAVE STARTED THIS THREAD IN THE "REPAIR" SECTION: MOVE IT IF YOU WISH TO. - David Lyga

 

[frank]

I don't know if the problem is under the top or bottom plate, but the bottom plate is easy to remove with no attached wires, so you could have a look-see. I once had an Olympus SLR that was jammed somehow, so I removed the bottom cover of that camera and of an identical camera that worked properly, and by comparing what was/was not happening between the 2 cameras, I was able to discern and fix the hang up. Good luck with this!

 

[David Lyga]

Believe me, frank, I would not have started this thread unless I had already removed both the top and bottom and tried, with magnifier, to find the problem. And, yes, I have made the comparisons with 'working' and 'nonworking' cameras. I KNOW that the solution is simple and broadcasting it here will help many. Thank you. - David Lyga

 

[Mark Crabtree]

I saw some information on this while looking for some other Pentax info. I can't recall if they actually told how to repair it, but I think the curtains aren't quite up IIRC. Shouldn't be hard to find with a Google search. Let us know if you find a fix.

 

[lxdude]

Here ya go, David. This is where I saw it explained.

www.kyphoto.com/classics/pentaxmeproblems.html

It looks like it's problem #1B., bent wind lock catch.


EDIT:For some more ME Super info from the same source:

www.kyphoto.com/classics/pentaxmeramblings.html

 

[David Lyga]

I will read this thoroughly and thank you, Ixdude.

I already am familiar with the 'wind lock' (and alreadly know that it has to be close to the center post in order for the shutter to be cocked) but could not find out what engages this wind lock because it is so buried with other stuff. This is the center of the problem but solving it might not be so easy. I will study this. - David Lyga

 

[darinwc]

I've fixed a couple of me supers with this problem. Pretty easy to watch the action of the levers and figure out what is going on. The link above describes it well. Don't even have to disassemble the assembly. Just use some wire benders to tweak the lever.

 

[David Lyga]

Figuring out the visible levers is not all that difficult to do. Last night I spent serious time looking over a junk ME Super body and comparing it with a working one. I managed to remove the front vinylette and remove the screws. I then pried the front mount section from the body.

The problem was not with the visible levers, but with the robust spring mechanism that actually cocks the shutter. This mechanism is just under the mount area and is not readily visible from the bottom of the body, because there is cast iron in the way. (If you have even taken the lens/shutter mechanism off a rangefinder you know all about the various iterations of this cocking mechanism which meshes with the body's link to the film advance lever.) But one of the visible levers extends underneath that cast iron and is guided by that shutter-cocking mechanism. That mechanism is supposed to remain close to the lens area when the shutter is cocked and released from that area only upon the firing of the shutter. This is what is failing.

Each time I would advance the film advance lever the 'catch' would not be made on that heavy-duty spring mechanism. The problem is deeper than I had thought and I think that each time film is advanced there is a tiny bit of bending that takes place that gradually obviates a proper 'catch'; such 'bending' is probably accelerated with 'aggressive advancing', as ixdude's article states. This is similar to the gradual filing down of an SLR door latch which, in time, can allow a dangerous amount of 'play', causing light leaks to be a distinct possibility. NOTE: this is why each time I open an SLR back, I first hold the door tightly with my index finger on the front of the camera and my thumb on the rear, both near the latch, and only then pull the full rewind upward to release that latch, without 'filing' it (thus, avoiding slowly wearing it down.)

No, I did not solve this problem but I learned a lot. Maybe in time I will be able to delve more deeply. But I do thank all for such imput, with can serve to solve lesser problems. The problem is entirely mechanical, but not easily reachable. - David Lyga