newfilm
Well-known
Dear all, thanks for all the help in my previous post in giving me enough pointer to finally fix the flash not fire on my MX earlier.
However while attempting the said endeavour things could have been perfect but alas my own stupidity now landed me on a new problem, let me explain:
I am reading the mx service manual, but I do still have some question if some of you guy who are alot more experience chime in:
If all else failed, at lease I hope my stupidity is a lesson for another, WATCH-OUT for those TINY washer!
However while attempting the said endeavour things could have been perfect but alas my own stupidity now landed me on a new problem, let me explain:
- while moving the front plate I failed to realise there are tiny brass washer underneath the plate (as shown in IMAGE 001)
- and I am stupid enough to cock the shutter and fire it (to test the flash contact), a few shoots later I notice my mirror no longer come down and curtain is not closing!
- Panic, using a torchlight trying to peer through the crevasse of the camera while slowly turning the thumb winding and there I saw it, a shinny reflection in the top of the curtain-drum (IMAGE 002)
- Using a tweezer pulling it out, and here I realise it was one of the tiny brass washer (shown in IMAGE 001)
- My panic subside, thinking a tragedy averted, since the flash contact is now clean and working now too, I'm happily putting everything back together.
- Holding my complete humpy dumpy back in my hand, put flash on its hotshoe, starts from 1/1000, each time the flash does fire!
- Work down to 1/60, the flash fire, but to my horror the mirror does not return!
- I then try every speed, and realise now any speed 1/60 and bellow including B the mirror and curtain will not return completely, any speed above will work (yes this is not gum up mirror bumper issue)
- I try to observe the curtain and notice one of the curtain is "slanted" (as shown in IMAGE 003), I'm sure it was not like that before, this must be due to the stuck washer in the curtain drum earlier and that did something to the curtain.
- So... now the camera is sitting on my table, fully assembled still, before I take it apart again, as you can see I am rather amateur in camera repair (fix one problem another surface), I'd like to ask pointer about how to "straight" up the curtain (as I assume it is the culprit why the mirror and curtain wont return when on slower speed), I plan to redo the following:
I am reading the mx service manual, but I do still have some question if some of you guy who are alot more experience chime in:
- maybe one of the string that suppose to pull the curtain is now slacking due to earlier "wrench in the wheel" problem.
- maybe some gear slipped? what might/should I be looking for?
- how does the curtain string manipulation happens, two string, one top and one bottom pulling or was it single point of pulley that pull both string as one?
If all else failed, at lease I hope my stupidity is a lesson for another, WATCH-OUT for those TINY washer!
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I wouldn’t worry about the flash not firing at higher speeds. I’m not particularly familiar with the MX, only having handled a couple, but with a cloth horizontally running focal plane shutter the maximum sync speed is only going to be a maximum of 1/60 to 1/125 at most anyway.
It looks a bit like a ribbon or cord has begun to detach, or, in the case of the latter, if used, perhaps has come off its pulley. It’s not going to be possible to establish the precise cause and best way of remedying the fault without some dismantling unfortunately.
Cheers
Brett
It looks a bit like a ribbon or cord has begun to detach, or, in the case of the latter, if used, perhaps has come off its pulley. It’s not going to be possible to establish the precise cause and best way of remedying the fault without some dismantling unfortunately.
Cheers
Brett
Here is a link from which you may retrieve a copy of the service manual for this model.
http://www.pentax-manuals.com/manuals/service/mx_sm.pdf
Examining the relevant pages of the document reveals it uses cords to pull the first curtain across the film gate. Given your comment about something getting caught up in the mechanism I can only assume a cord has either come loose from, or jumped off, its pulley.
The manual provides the information needed to align and fix the cord correctly. FYI
Cheers,
Brett