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Member Since 08 Aug 2008
Offline Last Active Sep 11 2014 06:28 AM

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In Topic: Z240 erratic behavior after 3 year - expectable?

07 July 2014 - 05:44 AM

Well after writing my previous posts I've been diving, and had the surprise to see both strobes were failing (either not shooting, or shooting too weak), whereas I would have expected the strobe connected with the right FO to behave well!

Then later in the dive all went back to normal, meaning both strobes worked perfectly, be it in TTL or manual, even the left one (the one which failed to trigger strobe on land).

Very strange! But anyways I've ordered two new FOs (35 EUR each), will shoot with them and see if I have any issues.


I'll report my findings here after a few shooting dives.


Thanks again for all the advice!

In Topic: Z240 erratic behavior after 3 year - expectable?

05 July 2014 - 11:09 PM

Thanks for the saliva advice Jim!

Any tips that can make this gear live longer is always welcome.


I just came back home and had a chance for some (dry) testing, and i am found it quite interesting:

1/ i cut the camera ends of the two FOs with a sharp knife, and right away did a simple test to point the strobe end of the FO at sunlight, and look through the camera end. With the high overall light it wasn't ideal, but i clearly saw a difference with my right FO showing me some light, and the left one nothing. I cut the left one again but same result. Huhu, could it be the problem source?


2/ i went to a darker place, stuck the 2 FOs in my housing, with the Olympus camera inside (no strobe attached for now). I shoot the internal fash (put 1/4th of it's power to ensure i can see), and looked at the strobe ends of the 2 FOs, side-by-side. 

Interestingly, my left (failing) FO was still transmitting some light, but much much less than the right (OK) FO.

So i detached the FO Inon strobe mount and did some cutting of the left FO on strobe end. But it didn't change anything, the left FO was still transmitting a weaker light.

Here my conclusion is that my left FO needs replacement as the weak point is probably somewhere in the mid-length, and i cannot spot it by inspecting the FO.


3/ then i thought i would still do some tests with the strobes attached now. After all, the Inon Z240s light sensors are reputed extremely sensitive, and if my eyes could see a tiny bit of light through left FO, my strobe would certainly catch it. 

The fact that it was weaker wouldn't concern me as strobe control is done based on how long the FO transmits light, not how intense the transmitted light is.

Well it turned out that whichever strobe received the left FO wouln't fire, at all!


My theory out of this:

I think that the light output transmitted in left FO got so weak that it reached the limits of the Inon Z240 sensitivity, and sometimes wasn't catcher at all. Remember that i had set my internal flash to fire at 1/4th of its power, so during a dive it would fire sometimes weaker (strobe wouldn't see), sometimes stronger (then it might see). 

I believe this could explain the "erratic" behavior i have observed, especially when shooting TTL (some of the pre-flashes not caught by one strobe).


Do you think it makes sense? Anyways i'll order a new FO and will find out.


It would be quite a relief as i thought "erratic strobe behavior" implies "costly internal electronics issue", but if i am right, it could be just one FO.


Also regarding the post-housing assembly checks, I'd have one recommendation for any user: when you shoot to test your strobes connectivity, make sure you position them in a way that you would notice if one strobe is off, or just weaker. What happened to me was that i was happy with my checks because i was doing test-shots against my garage's wall, with camera & strobes being quite close. Therefore, it was quite difficult to notice a faulty strobe, as just 1 strobe was sufficient to perfectly lit my wall.


I'll update you once i have tested with new FO.


thanks again for all the advice



In Topic: Z240 erratic behavior after 3 year - expectable?

02 July 2014 - 05:07 AM

Hi guys!


Many thanks for all these valuable feedbacks!

Let me answer to some of the comments:


Strobe internal issues - source?

Apart from errbrr, it seems that all of experienced reliability with your Inon strobes themselves (not mentioning the FOs here).

@errbrr, do you use eneloop batteries are are you careful not to shoot too many times in a row (the Inon Z240 manual is very cautious about that)?

I have always been using eneloop, and being careful with the shooting rate, so my issues shouldn't be due to strobes abuse…



I am bit reluctant to open the electrical connectors caps because I have never done so (never used them), so I assume they have always been water-tight. I will open them if I face issues again.



Indeed I have removed the rubber thing that holds FOs on housing side, and now it's definitely clean (maybe  it  used to be dirty and I removed the dirt last time I switched FOs in the pool (all subsequent shoots were fine).



Maybe it was just obstructing dirt on housing side afterwards, but if I experience some more issues I'll definitely cut the housing-sides of the FOs. Are you saying that a sharp knife would do the trick, or scissors? Is there any partiuclar way to shape the cut for light to travel better.

I am thinking this actually could be the cause, as among last weeks I have regularly removed/inserted my FOs from housing side (which I didn't do in the past), and have possibly damaged them.

Battery cells were fine I presume, as I charge them regularly, and the red ready light came on quite quickly.



So I've done this check to trigger the camera's internal flash, and made sure I saw some light in the FOs, on strobes side. This was after I removed and re-installed FOs on housing side, so again, I might have removed some dirt doing so.


Then if I still get issues in my next try-dive it means my FOs are erratically failing, which would really piss me off (I hate non-predictable equipment behavior, especially in diving!) @jander4454 what kind of 'erratic' did you experience with your FOs? Strobe fires fully vs. non firing at all? Or strobe fires fully vs. fires weakly? And did you manage to fix it just ripping-off the FOs end?


Thanks again for all the help!

In Topic: Z240 erratic behavior after 3 year - expectable?

29 June 2014 - 02:53 AM

One more thought: if we say that my problem was caused by fiber optics (and that my Inon dealer is very pessimistic about the products he sells), then how can i ensure that I won't have issues while diving, in terms of transmission of information via FO?


My post-camera assembly check routine included testing that both strobes where firing in TTL mode, and exposing properly my garage's wall, and clearly this test doesn't suffice as this could erratically work. However, i cannot do a dozen of those tests to make sure my system is stable, because the Z240s would heat up.

What about disconnecting the FOs from the strobes, look at them, and make sure i can see light from the camera's internal flash, on a few shots?

Does any of you do that?

Basically i am wondering if a FO that conducts light in a given position (meaning the FO plugs of my housing are clean enough) will keep conducting light (unless i twist it badly), i.e. can the FO itself be erratic?

In Topic: Z240 erratic behavior after 3 year - expectable?

29 June 2014 - 02:33 AM

I would not expect an issue with Inon strobe circuitry after such a short time unless you have had water in. I've had 2 x D 2000 for 9 years, diving most weekends and on holidays probably twice a year so over 1200 dives without any problem - I know it's not the same strobe but it is the same manufacture.
The only issues I've had has been with the fibre optic cables. Very occasionally I have managed to damage the end, usually next to the camera - that has allowed me to trim off a short section to a point above the break and things were great again. Once I had a break/damaged light path somewhere else in the cable that meant the cable only functioned intermittently
I suggest you obtain, on loan if possible, a FO cable that is new or you can be confident doesn't have a minor break somewhere and test you strobes with that before venturing down the strobe repair route. I'd also check that there id no water ingress at the electrical connection plug.

Thanks Jander! This is reassuring.
By electrical connection you mean i should check the pins used to plug an electrical sync cord? I've never used them but it cannot hurt to check.