Nitecore D10 error - always returning to lowest

Hi,
my Nitecore D10 has developed a problem: if I doubleclick to get to high mode, it gradually gets back to lowest mode; and if I press and hold the piston, it gets brighter for a split second, then returns to lowest.

So far I cleaned the piston and the body & reapplied lube, and cleaned the contacts on the head with isopropyl alcohol. And of course tested with several batteries, fresh from the charger.

Before that, there was sometime a clicking noise when turning the light on, so it could be that something in the head is stuck.

Any advice what to try next?

Have you gone through the PD troubleshooting checklist?

Also, what is the voltage of your cells?

Marduke said:

Have you gone through the PD troubleshooting checklist?

Click to expand...

No, where do I find it? Search didn't turn up anything

Also, what is the voltage of your cells?

Click to expand...

Both 1.2v NiMH and 3.7v 14500

balou said:

No, where do I find it? Search didn't turn up anything


Both 1.2v NiMH and 3.7v 14500

Click to expand...

There is a checklist posted in the MP.

I don't mean their nominal voltage, but the actual measure voltage. Also, have you removed the piston and inspected the piston exterior and body interior?

Marduke said:

There is a checklist posted in the MP.

Click to expand...

Ok, I first searched here, but I also can't find it over at MP, I used various combinations of nitecore/pd/piston with troubleshoot/checklist/troubleshooting

I don't mean their nominal voltage, but the actual measure voltage.

Click to expand...

Unfortunately I don't have my multimeter as I'm moving at the moment. But last time I measured the Ultrafire WF-139 had a voltage of 4.2v at the end of the charging cycle

Also, have you removed the piston and inspected the piston exterior and body interior?

Click to expand...

Yes I looked at it while cleaning. The piston got some tiny black spots on it, looks a bit like corrosion. Why do you ask? The black spots can probably be polished out

balou said:

Hi,
my Nitecore D10 has developed a problem: if I doubleclick to get to high mode, it gradually gets back to lowest mode; and if I press and hold the piston, it gets brighter for a split second, then returns to lowest.

So far I cleaned the piston and the body & reapplied lube, and cleaned the contacts on the head with isopropyl alcohol. And of course tested with several batteries, fresh from the charger.

Before that, there was sometime a clicking noise when turning the light on, so it could be that something in the head is stuck.

Any advice what to try next?

Click to expand...

First of all, double clicking = immediate low
Unless you meant click and hold = immediate high

Try pressing and holding harder and see if it works well, if not, I suspect the switch ring is not operating smoothly according to that clicking noise you mentioned, causing it to be stuck and thus the erratic behaviour. Contact your dealer and if possible, ask for a replacement. Or if you know how to fix the ring.... try removing it, clean it and insert it back. Not sure if that will break the warranty benefit though.

Hope this helps.

Try using your finger nail to push the ring to see if it smooth, if it not, then use the pin to move the ring around to make it smooth.

Isn't there any way to reset the electronics on D10? I have a Fenix LD20 that got stuck in a strange low mode. I had to take out the batteries and wait 20 sec before putting them back in to reset the electronics. And that worked.

Thought maybe it was a simlar procedure on Nitecore? If it's something wrong with the electronics of course...

I have had a similar problem with a D10. My short term fix was to loosen the tube ever so slighlty. It seemed that the piston was too long and was always pushing on the contact ring. I then played with the contact ring and that was a permanent fix.

Have you fixed it?

+1 on the moving the brass split ring. You may also want to put a small screwdriver or knife in the split and widen the gap slightly...

Report back...

Sorry for not replying sooner.
I tried moving the brass split ring, and widening it a bit with a screwdriver, without success at first.
Then a few days later, it just worked again - but only for a few minutes, at which point it started to continuosly cycle between high and low.

Then some times later, it accidentally rolled off my table. No damage done, and it's working again :thinking:

So for the moment it's fine again... but after this incident, the D10 has become more like a gadget than a trustworthy tool to me. When will it fail again? And how?