An odd fault only started this morning?

[Box Brownie]

Had a photo outing to Thursley Common with some fellow photographers....sadly poor to no-shows of anything of interest. But nice pub lunch

But oddly my OM1 with 300 & 1.4tc attached was misbehaving

It was fine last time out....
It would randomly switch by itself from C-AF to MF and no the MF clutch was not the reason. I even disabled the MF clutch in the menu to be sure.

When hanging down it was fine but when brought up to my eye it was on MF. A gentle shake I found could trigger the effect .......but not every time.

Using the top plate switch for setting the Focus type MF was locked i.e. could not shift it.

It was semi reproducible so will try without the TC and also my 40-150 f2.8 to see if it does the same.

At this stage no clear if lens only or both lens and body involved.

As I say it fine before today including when I was checking settings last night in readiness for the walk.

I wonder if anyone else has experienced this oddity?

[PeterSimpson]

Sounds like the contacts between the lens and body may need cleaning, I find iso-propyl alcohol works well.

I also enjoyed the pub lunch, as you said mostly bird backsides today!

Best wishes, Peter

[Box Brownie]

Hi Peter

I didn't know you were hereabouts

Thanks for your insight.

I will be initially checking the mechanical connections, as suggested on another forum the screws on the TC (and lens?) could have come a little loose.

As for iso propyl alcohol IIRC I still a thermal print head cleaning kit (from a previous job). But if it turns out to be 'mechanical' a clean just may not be required???

Cheers Laurence

[PeterSimpson]

Hi Lawrence,

Well, I'm all for belt and braces 😁, an iso-propyl alcohol clean is unlikely to do any harm and may be the fix you need.

Best wishes, Peter

[MJ224]

Yes, agree with you that loose screws should be looked at. Well worth checking regularly.

I had not a dissimilar problem recently. A good rub of the contacts seems to have sorted it.

Touch wood...

[peak4]

I sometimes get the same problem, which seems to be a mechanical/electrical interface issue, rather than a direct fault with any of the components.
Agree with the above on cleaning and loose screws, but don't tighten them if they are not loose.
There might be some sort of a thread locking compound, which will then be disturbed, fail and lead to loose screws in the future.

[Ross the fiddler]

Also check that all contact pins spring out fully too (body & MC14) as it has happened before that their action could be become sluggish or worse, collapsed spring (that normally only on cheap adapters etc).

[Box Brownie]

Thanks all for your replies.

I have now done my elimination tests:-

1. Trying without the x1.4 TC i.e. the bare 300mm
2. With my x2.0 TC
3. Putting the x1.4 TC on my 40-150mm f2.8

Note ~ both bare lenses are OK as is the case with the x2.0 TC in use on both lenses.

Thus the conclusion is that the cause is the x1.4 TC

In the quiet (I think I heard it in the field too?) as I lift the combo from hip height to my eye there is a clunk noise which I surmise is the lens IS disengaging due to a poor connection that also 'shows itself' by the switching from C-AF to MF.

I have visually inspected the sprung connectors and they are all 'up'.
However my PH0 screwdriver which I thought was the size to fit does not and surmise I need to get a set of JIT screwdrivers.
Can anyone throw some light on the size I need?

I will try to find my iso-propyl kit, it is in a safe place 🤔

Having said all that, it may be best sending it in for a service though pretty sure it long out of warranty! I wonder what the cost will be?

A bit annoying overall as it is my most used TC

[Ross the fiddler]

The size for the main screws is "0" but the small screws for the connection plate (camera side) is "00".
I'm using VESSEL No. TD-56S Precision Screwdrivers Set. https://vessel.co.jp/english/product/screwdriver/251389

[Box Brownie]

Many thanks for the pointer

I have found the TD-56S on Amazon so will order that set to check my Mc14 screws and the set will be a good addition to my toolkit

Edit ~ set ordered, should be here tomorrow......................will see if any screws are indeed coming a tad loose???

[Ross the fiddler]

Good news. I bought mine after similar discussions some time ago.

[Box Brownie]

Thanks also for the heads up re: two different size screws depending on the 'face' in question!

As mentioned and perhaps none too surprisingly the screws did not look(?) loose but if they did look loose I surmise the mounting to the lens and/or body would bind?
But if just loosened i.e. not tight there could be mechanical movement sufficient to display the fault I found.

Personally I hope they need tightening as if not it will for sure need a trip to the 'hospital' in Portugal.......... and a little checking & tightening easily done (as needed) by the owner saves money & time No different to sensor cleaning on digital bodies

[antpitta]

I bought a cheap set of small JIS screwdrivers on Amazon when my MC-14 screws started to slowly work loose - not sure the exact same ones are still listed but there are several still shown. Worked fine & I tend to check the MC-14 every year or so as this does seem to be the particular product that people report the problem with (and certainly the first thing I always check whenever there feels like a little play between body & lens!).

I also had to send my MC-14 in for repair when I virtually destroyed it in a fall in Columbia last November which partially bent/detached the TC mount from the rest of it. I expected that OM would declare it a write off but they "fixed" it and returned in a few days although as it was very shiny and had acquired a new serial number so you would think they just replaced the whole thing! No worries as the "repaired" item works fine and I've not even had any loose screw issues yet. Charge for the repair was £92.42 which seemed very reasonable.

[Punkawallah]

Thanks to this post I bought a set of those screwdrivers from Amazon. They arrived yesterday, first thing I did was check the MC14, sure enough three of the screws on camera side were very loose! In fact there was also a section of the O-ring showing, heart in mouth time, I carefully loosened all four screws and judiciously pushed the O-ring back in, re-tightened and all is good!
Also checked the other side plus all my lenses, some did tighten a little, well worth the price of the screwdrivers for peace of mind.

[Box Brownie]

I have checked the 4 screws on each end of the MC14 and none were loose.

So, for me it is going to have to go for a repair & service.

The fact that the fault happens as positional changes occur does infer something is "making & breaking" electrically. I wonder if there is a ribbon cable in there that is making intermittent contact?

As it is well out of warranty I will just have accept it is going to cost me!

PS no doubt they are all made in now in Vietnam but mine was made in the factory in China.

[Ross the fiddler]

I have checked the 4 screws on each end of the MC14 and none were loose.

So, for me it is going to have to go for a repair & service.

The fact that the fault happens as positional changes occur does infer something is "making & breaking" electrically. I wonder if there is a ribbon cable in there that is making intermittent contact?

As it is well out of warranty I will just have accept it is going to cost me!

PS no doubt they are all made in now in Vietnam but mine was made in the factory in China.

My MC14 was also made in China & was used with the 40-150 Pro lens until the MC20 came along it basically took its place (now I use mostly use the 100-400 lens instead), but I've not had a problem with the MC14.

On the mechanical side of it, the three leaf spings on lens mount side are there to keep a firm mount of the lens & I assume there may be a slight amount of movement possible if flexed hard enough. With these springs the mounting feels firm, but if they (or one) has collapsed then it might be physically possible to notice a less firm fit.

[Box Brownie]

My MC14 was also made in China & was used with the 40-150 Pro lens until the MC20 came along it basically took its place (now I use mostly use the 100-400 lens instead), but I've not had a problem with the MC14.

On the mechanical side of it, the three leaf spings on lens mount side are there to keep a firm mount of the lens & I assume there may be a slight amount of movement possible if flexed hard enough. With these springs the mounting feels firm, but if they (or one) has collapsed then it might be physically possible to notice a less firm fit.

Thanks for the added insights.

If one or more of those springs has lost its tension, hopefully the repair technician will be their (usual) diligent selves and determine the cause, if there?

Furthermore more I do hope that based on my diagnosis I will send with the item they will initially test and replicate the problem and thus know what needs replacing/repairing?

[rustyarrow]

My OM1 and the OM1,2 have done the same at odd times.