Pentax ME Super shutter problem

[Tim Hall]

I dug my old ME Super out the other day with the idea of running some XP2 through it. The shutter seems to fire as soon as it is cocked, which obviously isn't good.
Further investigation shows the problem only happens when a particular lens, a Pentax A 35mm -80mm.

The simple solution is to not use thst lens, but it would be good to know the cause. I'm somewhat stumped.

[drossall]

That's odd. Why would the lens cause that? What happens with no lens at all?

From memory (I've got two treasured ME Supers upstairs, but not used them for a fair bit), the shutter is electronic except the 1/125 setting or something, which is mechanical as a fall-back. What shutter speed do you have set, and is the button cell that powers the shutter OK?

[Tim Hall]

Works fine with no lens. Works fine with other lenses.
The button cells (2 x LR44) are OK-ish, but on their way out. The LEDs in the viewfinder are flashing. However, it does the same thing when set to M or 125x

It's only this lens that has the issue. It's an A series zoom lens, so the aperture ring can be set to A for fancy cameras (which the ME Super isn't) to control the aperture.

The other lenses I've tried it with are all M series - manual aperture only. I've tried a 80mm-200mm zoom, 28mm prime and 135mm prime and they all work just fine.

I've tried the lens on my K200-D digital body and is seems to work just fine, once I'd made the necessary tweaks to the body settings.

(Clutching at straws) maybe the problem lens is slightly distorted , causing a bit of flex in the body, triggering the shutter.

Anyhoo, a kind forumite has offered me a way out of this pickle by means of a donation of camera. I'd still like to know what's causing it though.

[FifeingEejit]

Has said lense ever worked with said body previously?

I note that this is an automatic aperture lense while the others are manual, could be incompatibility, could be a fault.

My thought would be to try another A lense on the body and try that lense on another manual ME.



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[drossall]

I certainly used A lenses with my (second-hand) ME Super, although my lenses were independent makes owing to budget. Later, I inherited my late father-in-law's kit - it was he who got me interested in the first place. I'm pretty sure (I could check) that he had an A standard zoom with his ME Super, and his kit was all genuine Pentax. That would suggest no systematic issue, but rather one specific to your individual example - but you probably guessed that.

[Tim Hall]

Having now got another ME Super, I can confirm it's an issue with the original body.  What the cause is,I don't know