This is just a theory and may not in fact have anything to do with the problems reported by users with this camera body.
All of our cameras contain an aperture control box which is an unit consisting of an electric motor and a plastic gear riveted to a metal switch. In repair parlance the motor is referred to as the charging motor and it functions to operate the mirror and shutter. As such it is synchronized hence the gear. This gear is riveted to a metal switch which is under spring pressure touching electrical contact points. There are two rivets both of which are plastic securing this part of the assembly. The gear is indexed to provide for synchronization of the mirror and the shutter.
Two things may happen which in theory could cause the err message, freezing mirror, and/or exploding shutter or combination of any of the three things.
1) The simple thing is that lubricant could bleed onto the gear and metal switch causing a situation of no electrical contact setting off the err message and/or freezing the mirror or shutter. This may be because of substandard lubricants, excess lubricants, or exposing the camera to excessive heat which cause the bleeding. This causation would lead to an intermittent problem (that many people report) or maybe, in the case of excessive lubricant leaching, no electrical contact until degreased.
2) Another possibility is that one or both of the plastic rivets give up the ghost releasing the spring tension between the switch and contacts. This also causes a situation of setting off the err message and/or freezing mirror or shutter. This causation would lead to failure until repaired.
To R&R an aperture control box requires disassembly all the way from breaking the block open down to removing the mirror box and would run about $300-$400.
I think the theory explains why many 750 users have perfectly functioning cameras - they have neither causation. Excessive grease may be due to improperly or poorly trained employees at that point in the line whose work slipped passed QC or maybe a good employee who over oiled a few after a night of to much sake or something. The second causation is a little known problem, at least to the general public, with previous canikon bodies mostly in the early days of the dslr. It is well known to repair techs however and lucrative for them.
I think Nikon remains sort of mum about the deal because if they blurted out about it they would probably receive a bunch of cameras that did not need repair but would require about 3 hours labor to find out and with the risk of pulling lose some wire or causing some other problem with a perfectly working camera.
I am leaning towards the lubricant as the major issue because of two things. One the D600 debacle and two good lubricant is high dollar.
As I said it is just a theory after pondering and researching the problem for quite some time but it could be something entirely different. It has changed my opinion on the D600 and D750 somewhat.
All of our cameras contain an aperture control box which is an unit consisting of an electric motor and a plastic gear riveted to a metal switch. In repair parlance the motor is referred to as the charging motor and it functions to operate the mirror and shutter. As such it is synchronized hence the gear. This gear is riveted to a metal switch which is under spring pressure touching electrical contact points. There are two rivets both of which are plastic securing this part of the assembly. The gear is indexed to provide for synchronization of the mirror and the shutter.
Two things may happen which in theory could cause the err message, freezing mirror, and/or exploding shutter or combination of any of the three things.
1) The simple thing is that lubricant could bleed onto the gear and metal switch causing a situation of no electrical contact setting off the err message and/or freezing the mirror or shutter. This may be because of substandard lubricants, excess lubricants, or exposing the camera to excessive heat which cause the bleeding. This causation would lead to an intermittent problem (that many people report) or maybe, in the case of excessive lubricant leaching, no electrical contact until degreased.
2) Another possibility is that one or both of the plastic rivets give up the ghost releasing the spring tension between the switch and contacts. This also causes a situation of setting off the err message and/or freezing mirror or shutter. This causation would lead to failure until repaired.
To R&R an aperture control box requires disassembly all the way from breaking the block open down to removing the mirror box and would run about $300-$400.
I think the theory explains why many 750 users have perfectly functioning cameras - they have neither causation. Excessive grease may be due to improperly or poorly trained employees at that point in the line whose work slipped passed QC or maybe a good employee who over oiled a few after a night of to much sake or something. The second causation is a little known problem, at least to the general public, with previous canikon bodies mostly in the early days of the dslr. It is well known to repair techs however and lucrative for them.
I think Nikon remains sort of mum about the deal because if they blurted out about it they would probably receive a bunch of cameras that did not need repair but would require about 3 hours labor to find out and with the risk of pulling lose some wire or causing some other problem with a perfectly working camera.
I am leaning towards the lubricant as the major issue because of two things. One the D600 debacle and two good lubricant is high dollar.
As I said it is just a theory after pondering and researching the problem for quite some time but it could be something entirely different. It has changed my opinion on the D600 and D750 somewhat.
