My Nitecore D10 won't turn off

I know I have seen threads on Nightcore PD light problems and repairs, but when I searched for Nitecore I found way too many threads, and searching for D10 gives zero results:sigh:
I just got a Nitecore D10DGP a couple weeks ago. It seems to work fine, but tonight I noticed that when it's turned off, the LED still glows and flickers very, very dimly. I can only see it looking directly into the LED.
The only way I can get the LED to turn all the way off is to unscrew the head.
I also have an EX10GDP and it does not do this. It turns off completely without having to unscrew the head.
Has this been covered before? If so, can anybody point me to the thread?
Any suggestions?

Sorry about your trouble's I had a EX10 with the exact same problems and had to send it back.

I'm not sure, but sounds like a drainage. Have you checked that the switch ring is not stuck? Rotate it a bit. If not, as suggested, send it for inspection/repair. The only time when I saw this happened is when damage's done to the LED by overdriving it.

I'm sure I've seen at least a few reports of this issue on the D10. I thought it was on the Q5 or R2 models but the problem is likely unrelated to the type of emitter. There is some slight electrical contact or bleed-through current causing this when the light is turned off - guess you could call it a short - and the best solution is to return the light for replacement.

Thanks for the replies.
I gently moved around the split ring and it appears to be clean and free; it moves easily. I took out my AW 14500 battery and put in a NiMH AA cell. With the NiMH, the problem seems to go away. I put my AW LiIon back in and turned it on and off a bunch of times. Most of the time it seems to work OK, but every once in a while, when I turn it off, the LED flickers and sputters very dimly and does not go all the way off.
I sent an email to Nitecore.

I'd also suggest lubing the piston tube and the o-ring near the base. Maybe it is just sticking a little, but I'd expect the light to stay fully on if that were the case.

i will typically unscrew a light a half/full while not being used.
or remove the battery.

Lemon328i said:

I'd also suggest lubing the piston tube and the o-ring near the base. Maybe it is just sticking a little, but I'd expect the light to stay fully on if that were the case.

Click to expand...

It was a bit sticky when I first got it. I cleaned off most of the factory lube from around the end of the tube around the pushbutton and now it is silky smooth.

waddup said:

i will typically unscrew a light a half/full while not being used.
or remove the battery.

Click to expand...

I know the piston drive lights have a light draw from the battery when they are off so I also keep mine locked out when they are in the drawer. I just happened to notice this problem in my D10 while I was using it last night.