marknorton Posted April 18, 2010 Share #1 Posted April 18, 2010 Advertisement (gone after registration) A problem which has been reported from time to time is when the camera continually tries to re-cock the shutter and after 3 or so attempts, gives up and displays the error "Shutter Fault". This happened to my long suffering M8 yesterday which has otherwise been working well in spite of its various traumas though I am about to send it back to Leica to have the sensor alignment adjusted to current practice. I thought I would show you what (in my case) caused the error and how I fixed it, not that you will necessarily want to dive in yourself but to help anyone with this problem understand what's going on. When the motor cocks the shutter, it also primes the release mechanism which fires it. Here is the release mechanism in the primed (top) and unprimed state: Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! There's a combined magnet/electro-magnet and a lever with a pivoted armature. When primed, the electromagnet is not in use and the magnet grips the armature which makes contact with both pole pieces of the magnet, in effect completing the magnetic "circuit". When the shutter is released, a pulse of current through the electromagnet cancels the effect of the permanent magnet and the lever is released. This allows the grey lever bottom right to actuate the shutter itself. The shutter error occurs when repeated attempts to cock the shutter do not succeed in priming the release mechanism. The lever is moved towards the magnet but it doesn't grab the armature to latch the release mechanism in the primed position. The microprocessor is able to confirm whether this has happened using a position sensor on the back, you can see the connections to it at the top. If the microprocessor doesn't see the expected confiirmation, it retries the recocking process. The reason, in my case, why the mechanism did not latch was because the armature was not always making contact with both pole pieces, only one. You can see that it relies on the armature being pivoted in the middle so that as the lever moves towards the magnet, contact with first one, then the second pole piece is made, the magnetic circuit is closed and the magnet grips the armature. The problem was all down to that white silicone. Why it is there, I do not know. It may be there to dampen the rotation of the armature or limit its extent to prevent the mechanism jamming but it appears that, over time, it may have hardened and was limiting the movement to the extent that contact was not made with both pole pieces and the mechanism failed to latch. The solution in my case was simply to dig out the silicone leaving the armature to rotate freely and the shutter is now working correctly. I just need to check if there's any possibility of it rotating so far that the mechanism jams in which case I'll devise a better way of limiting it. I feel certain that this part will, by now, have been modified or redesigned, possibly as part of the M8.2/M8u/M9 shutter upgrade. It's buried deep in the camera behind the lens release button so not a trivial job to find out! Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! There's a combined magnet/electro-magnet and a lever with a pivoted armature. When primed, the electromagnet is not in use and the magnet grips the armature which makes contact with both pole pieces of the magnet, in effect completing the magnetic "circuit". When the shutter is released, a pulse of current through the electromagnet cancels the effect of the permanent magnet and the lever is released. This allows the grey lever bottom right to actuate the shutter itself. The shutter error occurs when repeated attempts to cock the shutter do not succeed in priming the release mechanism. The lever is moved towards the magnet but it doesn't grab the armature to latch the release mechanism in the primed position. The microprocessor is able to confirm whether this has happened using a position sensor on the back, you can see the connections to it at the top. If the microprocessor doesn't see the expected confiirmation, it retries the recocking process. The reason, in my case, why the mechanism did not latch was because the armature was not always making contact with both pole pieces, only one. You can see that it relies on the armature being pivoted in the middle so that as the lever moves towards the magnet, contact with first one, then the second pole piece is made, the magnetic circuit is closed and the magnet grips the armature. The problem was all down to that white silicone. Why it is there, I do not know. It may be there to dampen the rotation of the armature or limit its extent to prevent the mechanism jamming but it appears that, over time, it may have hardened and was limiting the movement to the extent that contact was not made with both pole pieces and the mechanism failed to latch. The solution in my case was simply to dig out the silicone leaving the armature to rotate freely and the shutter is now working correctly. I just need to check if there's any possibility of it rotating so far that the mechanism jams in which case I'll devise a better way of limiting it. I feel certain that this part will, by now, have been modified or redesigned, possibly as part of the M8.2/M8u/M9 shutter upgrade. It's buried deep in the camera behind the lens release button so not a trivial job to find out! ' data-webShareUrl='https://www.l-camera-forum.com/topic/118571-m8-shutter-error-causefix/?do=findComment&comment=1297410'>More sharing options...
Advertisement Posted April 18, 2010 Posted April 18, 2010 Hi marknorton, Take a look here M8 Shutter Error - Cause/Fix. I'm sure you'll find what you were looking for!
papimuzo Posted April 18, 2010 Share #2 Posted April 18, 2010 Thanks Mark, once more for your pictures/explanations. I certainly will not try to verify by myself, but at least I can understand.... how complicated my M8 (M9 soon??) is and how numerous are the ways of perturbing it... Quote Link to post Share on other sites More sharing options...
thai.charlie Posted April 18, 2010 Share #3 Posted April 18, 2010 hmm. so is this why it takes leica 2-3 months to fix it? leica NJ has mine for almost 2 months now. Quote Link to post Share on other sites More sharing options...
farnz Posted April 19, 2010 Share #4 Posted April 19, 2010 hmm. so is this why it takes leica 2-3 months to fix it? leica NJ has mine for almost 2 months now. It's okay, thai.charlie, NJ will have read Mark's explanation of how to fix the problem and you'll have your M8 back soon. Pete. Quote Link to post Share on other sites More sharing options...
marknorton Posted April 19, 2010 Author Share #5 Posted April 19, 2010 I'm sure Leica painstakingly added the silicone for a reason, though I do not know what it is. I feel certain later production is different. As luck would have it, after three years of being dismantled and put back together and the indignity of having 30 wires come out through the lens throat at one point, this M8 has finally thrown in the towell! I've got what we used to call Silent Death Syndrome where the camera is dead and just gets very warm on the back on the right as the battery drains very quickly. The camera is drawing more than 1A at this point and the battery lasts about 30 minutes. As I recall, this problem was down to a transistor failure and was corrected by Leica in later production. I think I'll retire it after a hard life! 1 Quote Link to post Share on other sites More sharing options...
steich Posted April 19, 2010 Share #6 Posted April 19, 2010 (edited) this M8 has finally thrown in the towell!I think I'll retire it after a hard life! Thanks again Mark, IMHO Leica should appreciate your "M8 CIS" work and send you this new transistor. Or maybe offer you a "digital CLA" at a very friendly friendship price.... BTW, wasn't there someone from VERY close to the top of that company who wrote a very enthusiastic comment ("a brilliant piece of so to say reverse engineering, thanks!") on your anatomy thread? Stefan Edited April 19, 2010 by steich Quote Link to post Share on other sites More sharing options...
marknorton Posted April 19, 2010 Author Share #7 Posted April 19, 2010 Advertisement (gone after registration) Yes, Leica have been very good natured and I've had a couple of messages... I'm a burden most other camera vendors don't have to carry! Quote Link to post Share on other sites More sharing options...
papimuzo Posted April 20, 2010 Share #8 Posted April 20, 2010 I think I'll retire it after a hard life! No Mark, this old boy deserves certainly a last surgery in order to give it another life! I'm sure that you can repair it; after that you should leave it in peace;). Thanks anyway to you and IT Quote Link to post Share on other sites More sharing options...
menos I M6 Posted April 24, 2010 Share #9 Posted April 24, 2010 Thanks Mark for the post! Your dissections are always a pleasure to follow and don't give up on that M8! Quote Link to post Share on other sites More sharing options...
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