Will your D20 turn on by shaking?

Recently I found my Nitecore D20 will turn itself on just by slight shake or minor shock. It didn't happen before. I think I read somethere that somebody's D20 will turn on by hit on tail, but my D20 will turn it on just by most casual shake...

I changed my battery from Energizer rechargeable to alkaline, now I need more shaking to turn it on. My energizer may be longer than alkaline a tiny bit.

My first run D10 does this every now and then, after a year of light use on rechargeable AA. It would turn on / off, flicker wildly, ramp up / down, when shaken or lightly tapping the tail end.
I contacted 4Sevens who suggested squirting a small amount of contact cleaner into the head's electronics. [They also welcomed me to send the torch back to them]. This worked for a month or two, until the problem reappeared. I did the contact cleaner thing again, and (another month or two later) it has been fine so far.

I've just violently shook my D20 and tapped the tail hard against my palm. Doesn't turn on. :shrug:

nope

Q5 d20 here.

Its a little dependent on the weight of the batteries. When bumped, the + battery contact separates from the + head contact for a split second, causing the light to come on.

This could have been corrected by adding smarts to the circuitry, but I dont know if they have done so.

IMHO, this is the only big annoyance with this light.

It can be slightly resolved by adding a spring to the + head contact. It also helps to stretch the spring in the bottom of the piston a little bit.

Same as csshih and Zeruel. No problems at all with my D20 R2. :shrug:

OK, I used a screwdriver to push the spring in the battery tube a little bit, then the spring fell off...And I can't put it back.

Finally, I put the spring back, but not perfectly centered.

I put a very thin steel spring around the (+) terminal of the light, which is just enough to maintain an electrical connection when the battery shifts backwards. This mod eliminates the problem. The only other "solution" is to unscrew the head after each use.

EngrPaul said:

I put a very thin steel spring around the (+) terminal of the light, which is just enough to maintain an electrical connection when the battery shifts backwards. This mod eliminates the problem. The only other "solution" is to unscrew the head after each use.

Click to expand...

please note that the steel spring will have to be almost the perfect size or you'll risk shorting out your light.

csshih said:

please note that the steel spring will have to be almost the perfect size or you'll risk shorting out your light.

Click to expand...

True, there are a few components and solder joints nearby...

This one hugs perfectly!

I pulled the spring off mine first try too. Luckily the whole piston comes unscrewed if I remember correctly, and it is easy to put back...

Mine didn't until it came back from repair :shrug:. I've now taken to unscrewing the head when not in use - something I shouldn't have to do. One of my D10's is acting up now (off warranty now, of course) but my other is still good as new. That leaves me with a 33% success rate with the PD series. I love my working D10 and use it everyday, but I can't trust the others anymore. Its back to proper switches for now

I had to send back 3 D20's because they failed either out of the box or after a tiny bit of use. One of them just kept getting dimmer, the other just quit while it was running. (These I never put a spring on.)

As for D10's and EX10's, never had a problem.

On all the models, holdin momentary on a low or medium mode always results in a jump to high after a second or two. I hate this, sometimes I want momentary mode at a moderate level. :thumbsdow

EngrPaul said:

I had to send back 3 D20's because they failed either out of the box or after a tiny bit of use. One of them just kept getting dimmer, the other just quit while it was running. (These I never put a spring on.)

As for D10's and EX10's, never had a problem.

On all the models, holdin momentary on a low or medium mode always results in a jump to high after a second or two. I hate this, sometimes I want momentary mode at a moderate level. :thumbsdow

Click to expand...

Now that you mention it, I remember mine does that too. I always thought it was my fault for not pressing the piston hard enough.

EngrPaul said:

I had to send back 3 D20's because they failed either out of the box or after a tiny bit of use. One of them just kept getting dimmer, the other just quit while it was running. (These I never put a spring on.)

As for D10's and EX10's, never had a problem.

On all the models, holdin momentary on a low or medium mode always results in a jump to high after a second or two. I hate this, sometimes I want momentary mode at a moderate level. :thumbsdow

Click to expand...

Maybe there is some intermittent connection problem in your holding, so the light think you are jumping to high...

My first D20 often stuck itself and can't be pushed. The replacement works perfectly, until now. I think the smart PD system rely on too much mechanical factor to get complex UI behavior, but mechanical system is not that accurate for this task. The original idea is good, and a working PD system have pretty feel in operating, but I may look for a normal switch system for my next light...

@dracodoc, If you have a nitecore PD, give it a try.

Go to a low mode and untwist the head until it shuts off. Press and hold. You will get your previous light level for a second, and then get blasted with full.

The only way to get back to low is tighten the head, get blasted again, and rapidly pump the piston.:thumbsdow

EngrPaul said:

I had to send back 3 D20's because they failed either out of the box or after a tiny bit of use. One of them just kept getting dimmer, the other just quit while it was running. (These I never put a spring on.)

As for D10's and EX10's, never had a problem.

On all the models, holdin momentary on a low or medium mode always results in a jump to high after a second or two. I hate this, sometimes I want momentary mode at a moderate level. :thumbsdow

Click to expand...

Yes, if you depress the piston until it stops, you'll basically be initiating either a ramp up/down, or (if you fully depress it less than a second after you turn the light on) you'll jump to max. If you hold down the piston anywhere in the middle of its travel, you can maintain a custom-level momentary activation. To make it a little easier on yourself, try unscrewing the bezel a bit more than normal. This will extend the piston's range of travel, and make it easier to maintain your custom light level. Remember, holding the piston down all the way, regardless of whether the bezel is tight or loose, is telling the light to change brightness levels.

This kinda works, but I have to turn it past the o-ring and then it ramps anyway. On one the head popped off when I turned it back far enough...

EngrPaul said:

This kinda works, but I have to turn it past the o-ring and then it ramps anyway. On one the head popped off when I turned it back far enough...

Click to expand...

Hmm, so you're saying that even if you touch the piston *just* enough to turn the light on, it'll change brightness levels? In this case, the D20 must be different than the D10 that I have. I'm sorry if I didn't clarify that. I do have a D20 on its way to me, and when I get it I'll have to test it to see how it reacts in momentary mode. I just ASSumed that the two lights would act the same, seeing as how they share the same UI.

Come to think of it now, I do recall that the D20 uses a different piston design, and I think the piston travel is limited by a channel in the body tube. D'oh! Sorry for the confusion, I just jumped to conclusions before i considered all the facts. I guess my love for the D10 clouded my judgment a little!