NDI- strobe issues

BabyDoc

Flashlight Enthusiast
Joined
Jan 29, 2008
Messages
1,245
Location
Beachwood, Ohio
I have a new NDI which occasionally goes into strobe mode when it should not. If I am in steady high output mode (bezel tight), and loosen the bezel to get into the user definable mode, occasionally (once in 20 times), the light goes into strobe mode instead. I have cleaned the contacts numerous times and yet occasionally with no predictability the light fails to switch down properly into the programmable mode; it strobes instead until I tighten and losen the bezel to get it out of strobe mode. Has anybody else experienced this with their NDI? I know that I am smoothly loosening the head, so it is not any jiggling back and forth movement that is causing it to go into strobe when I loosen the head. Any ideas?
 
I believe mine did this when the light was new and the twisting action was stiff because of the o-ring. It didn't allow you to quickly twist the head to break contact cleanly and keep this from happening.

Some here, as you may have read, replaced the o-ring with a smaller one with good results. Not necessarily for this reason, but to just make the head twist easier. I had my own fix that I posted here. http://www.candlepowerforums.com/vb/showpost.php?p=2309534&postcount=202

The twisting action on mine feels like butta' now and I have no mode switching issues.

Edit to add: You can sorta test this theory by removing the o-ring and see if that helps. :)
 
Last edited:
The head on my NDI turns quite smoothly, like butta, too! Mine was a bit hard to turn when I first got it, but there was no lube in it from Nitecore. I did lube the threads with Nyogel 760 and the O ring with Nyogel 779. After doing so, the head on my Nitecore will turn so easily, I can turn the head holding and turning with just one hand. Still, I generally turn using both hands to get quicker switching. In your old post, you mentioned that the threads should not be lubed? Why? It's funny but Nitecore says to clean and lube the threads in the maintenance instructions; it doesn't mention lubing the O ring.

I do agree, however, the O ring is the problem with the tightness some people experience. I didn't have to sand down my O ring as you did. I only lubed it. Perhaps the O rings in the 2nd run lights are not as thick as were in the first batch of lights. In any case, unless the lubed threads ARE the problem, I still can't figure out why I occasionally have the switching problem. It isn't a big deal, since it happens infrequently. I just hadn't heard others having this problem of getting a strobe when attempting to switch from high level to the user defined light level.
 
Last edited:
Make sure all the contact points are clean, and make sure when you go to turn it, turn it quickly. If you are kinda slow to loosen it, it may break the contact and make contact again with the tactical mode, then break again, etc.
 
The head on my NDI turns quite smoothly, like butta, too! Mine was a bit hard to turn when I first got it, but there was no lube in it from Nitecore. I did lube the threads with Nyogel 760 and the O ring with Nyogel 779. After doing so, the head on my Nitecore will turn so easily, I can turn the head holding and turning with just one hand. Still, I generally turn using both hands to get quicker switching. In your old post, you mentioned that the threads should not be lubed? Why? It's funny but Nitecore says to clean and lube the threads in the maintenance instructions; it doesn't mention lubing the O ring.

I do agree, however, the O ring is the problem with the tightness some people experience. I didn't have to sand down my O ring as you did. I only lubed it. Perhaps the O rings in the 2nd run lights are not as thick as were in the first batch of lights. In any case, unless the lubed threads ARE the problem, I still can't figure out why I occasionally have the switching problem. It isn't a big deal, since it happens infrequently. I just hadn't heard others having this problem of getting a strobe when attempting to switch from high level to the user defined light level.

I had this problem (strobing occasionally) when I first got my light as well. I also lubed the threads with Nyogel. The threads on mine have been clean (except for a little De-Oxit Gold) for about 3 months now and I have not had one problem at all with the light and it gets used numerous times daily at work and home.

The threads shouldn't be lubed because they are part of the circuit and lubing with something like Nyogel may cause the circuit to not be as conductive as it needs to be. I cleaned off all Nyogel with a thick rag and then followed with De-Oxit red to clean the threads to a pristine condition. I then put a little De-Oxit Gold on them for protection and all is well for months now. I absolutely love this light as my EDC.

Edit: I forgot to mention that I swapped an o-ring from one of my 2xAA Minimag lights and it made my NDI head turn like butta.
 
Last edited:
Just turn the light off before going into user mode, then turn it back on. Not really a big deal. Especially if it only does it one out of 20 times. It's because of poor contact when you twist the head. The light thinks the battery is low and goes into low battery warning.

Bill
 
I am using NIMH Eneloops. I didn't think you get a low battery warning with anything but Lithium cells.
 
I understand what your saying. It is not a real battery warning. It is just the light thinking it is because it loses contact at some point when you are turning the head. I read a thread on this behaviour sometime ago. someone else was complaining about it and Nitecore answered the complaint. There is a lot of material on this light on CPF so I'm not sure how easy it will be to find.

Anyway my personal opinion is your light is OK. If you like everything else about it, I wouldn't worry about it.

Good luck.

Bill
 
OK, I have tried just about every suggestion here, one at a time. I removed the O-ring. It still mis-switched occasionally. I replaced the O-ring with one from my p2d. The head actually turned worse. I replaced it with the original one. I cleaned all the threads THOUROUGHLY and replaced the head, ONLY lubing the O-ring. Still no difference. I purposefully turned the head slowly trying to see if it misfires more often than if I turned it quickly. It makes no diffence in the frequency of miswitching. The only thing mentioned here that I have not tried is Deoxit. I don't have it to try. Could that be the REAL difference? Is it really worth using? might just get some. In the meanwhile, the suggestion to change modes with the power off seems sensible and fail proof.
 
not that i doubt your ability or anything, but you know, we all have our moments..:crazy:

how much are you loosening the head? cos if not enough, then its maybe just at that point where it switches over?

other then that...i got no idea..:)

Crenshaw
 
The threads are conductive, they should not have any lube on them. Lube can lead to intermittent electrical contact. Also, try turning the head more than just 1/8 turn. Try 1/4 turn.
 
The only thing mentioned here that I have not tried is Deoxit. I don't have it to try. Could that be the REAL difference? Is it really worth using? might just get some.

I think it is. I never used it before about a year ago at the suggestion of someone on CPF and now use it on all electrical connections that operate in the lower DC voltage ranges. I think it makes a huge difference. I got mine from a fellow CPFer 4sevens store fenix-store.com. I ordered the 2-pack with one of each (I actually ordered 3x2-packs). Didn't even know he had the stuff until a few months ago. I'd use the small tubes vs. the spray cans elsewhere on the web. I first tried the spray cans and it wasted a lot as well as one of the cans losing it's propellant rendering about half the can useless. YMMV
 
I finally figure out why my light is mis-switching. It is not a matter of loosening the head too slowly that causes the light to strobe. It is a matter of not tightening the head quite enough when going into high mode to begin with. I guess I have been too gentle tightening the head. It will make enough of an electrical contact to put the light into high even before the head is completely tight. When switching back from that position, the light mis-switches. Being careful that the head is fully tightened in high, has eliminated every misfire, no matter how slowly I loosen the head. BTW, I replaced all the lubes. Nyogel is supposed to be conductive and the light seems much smoother with it.
 
Last edited:
There is another condition that can cause unwarranted activation of the strobe or inadvertent ramping.

If the head is only slightly loosened, brief, inadvertent vertical pressure on the head can cause accidental activation of ramping and strobe.

Try it. Back off the head slightly from fully tight then very briefly push the head down and release. It may take a few tries.

So bumping the head can trigger ramping.

I can't reliably duplicate an instance I had of it inadvertently strobing but I am sure a head bump triggered it in hindsight.

The solution is just to ensure the head is backed of a half a turn rather than just e little.
 
I tried moving the head up and down but can't get it to either ramp or strobe as a result of that movement. My O ring is snug enough there really isn't very much play up or down with the head nearly fully tightened.

There is a point during tightening that the head, although not quite tight, the light will go into high mode. I suspect that the contact points are not perfectly parallel at that point and there is only partial contact. Loosening from that point of partial contact, could, even with a quick twist, causes contact instability or movement which triggers the strobe. Tightening the light more completely probably brings more of the contact surfaces together making it harder for the conections to shudder when loosened.
 
Top