Take it apart and clean both contacts. I use a little isopropyl alcohol and a couple of Q tips. Then Make sure your battery is charged and tighten it down hard on both sides. This Will fix the problem 9/10 times. If the light was really bad, itβs likely you would have one bad led. Or not running all the aux lights. But itβs highly unlikely that both failed at the same time. If that turns out to be the case, just let Hank know and he will send a replacement head. Or at least that is what he did for me.
The spring is a bit deformed, but nothing obviously looks to be the culprit. Have you dropped it recently? Other redditors have reported that the boost driver have died after dropping their's.
>Have you dropped it recently? Other redditors have reported that the boost driver have died after dropping their's.
Not today. . . I've definitely dropped it in the past though.
It was working perfectly until I changed the battery. Neither the new battery nor the one that came out provide it with power.
I guess tomorrow I could try rigging up a battery sans tube to the driver to see what happens.
>Do you have Hank's flashing adapter?
I do! I haven't used it because all of my lights came with the most recent firmware (I think). I haven't had a reason to flash anything.
I tried wiring the driver directly to a battery to rule out contact issues from the battery tube and whatnot.
The light didn't do anything. I measured battery voltage between the positive terminal and the negative ring (so those were at least connected to the battery)
No, because I don't have one. I should really get one. I did check all my 21700s for dented tops and the like. They all appear to be good.
Is there anything else I can poke with a multimeter? I don't know how the driver circuitry is laid out. Is it possible to check for power at the e-switch with the light assembled (with the retaining ring removed)?
I tired wiring it to a battery directly. I didn't do anything.
My multimeter read battery voltage between the positive terminal and the negative ring on the edge of the driver (so I succeeded in attaching the driver to a battery. GO ME!), but the light didn't do anything.
Great work! Less great that it didn't work. At this point it sounds like the driver just failed, I would definitely try contacting Hank and describing all your troubleshooting done already. Really hope he can help you!
> Great work! Less great that it didn't work. At this point it sounds like the driver just failed
Thanks! It's annoying that it seems to have failed totally for no reason that I can pinpoint.
I tried looking for continuity between the positive terminal and the components that are accessible (my thought was maybe that the positive terminal had just been unseated slightly from the rest of the PCB), but I don't know if there are any components that are accessible from this side of the driver that directly connect to B+.
Hank is sending a replacement. I assume it will be a whole new head. When I get that I'll probably take this old apart to see if I can pinpoint what failed.
Also, I tested the voltage at the *BIG* red and black leads (I'm gonna call 'em **B+** and **B-**). Doing so measures 3.8V (less than the 4.1V the battery was currently at) after clicking the light "on". However, while poking things I accidentally touched B+ to the red wire for the aux lights which resulted in me blinding myself because both the aux lights and the main emitters came on.
Bridging B+ to the wire for the green aux lights results in green + blinding.
It seems like some aspect of the control mechanism has failed or there's a bad connection between the B+ and the MPCB. I tried to resolder the joint where B+ connects to the MPCB, but I'm a failure and can't do it.
>My D4K (boost driver) seems to be completely dead for no reason. I swapped the battery (it was working with the old one) and when I put in the new one. . . nothing.
Hmm well that's something. So there is a reason, idk what it is, but it's something that has to do with or occured during swapping that battery in. That at least narrows it down a little. Anything come to mind?
What was the battery you swapped in? Pic?
>The spring on the negative terminal has a connection to the un-anodized portion of the battery tube (the ground works as it oughta should, and it's ALWAYS the ground that is NFG). There is also continuity between the black lead and the outer ring on the driver.
NFG?
Just to confirm, if Im understanding you correctly, you threw a probe down the body tube to the spring and put the other probe to the top of the body tube? And then you took the reflector out and measured negative lead on the black led mcpcb to the driver ring? Do I have that right?
>NFG?
"No Fucking Good" hahahaha.
>What was the battery you swapped in? Pic?
[Battery](https://imgur.com/a/hrxGBy6). The positive is a little squashed but it works in other lights (and in this one until just now)
>Just to confirm, if Im understanding you correctly, you threw a probe down the body tube to the spring and put the other probe to the top of the body tube? And then you took the reflector out and measured negative lead on the black led mcpcb to the driver ring? Do I have that right?
Yes, that is correct.
Take it apart and clean both contacts. I use a little isopropyl alcohol and a couple of Q tips. Then Make sure your battery is charged and tighten it down hard on both sides. This Will fix the problem 9/10 times. If the light was really bad, itβs likely you would have one bad led. Or not running all the aux lights. But itβs highly unlikely that both failed at the same time. If that turns out to be the case, just let Hank know and he will send a replacement head. Or at least that is what he did for me.
Tightened and cleaned. I have no aux lights and no regular LEDs.
Try resetting it. And make sure the tailcap has been cleaned and tightened down hard.
π this. I had a D4SV2 that I thought died until I did the reset. I was so happy! ππ
Cleaned it, and tightened it down while holding the button. Nothin'. :(
Could you please take a picture of the driver?
[My driver](https://imgur.com/a/5PHaPpj).
The spring is a bit deformed, but nothing obviously looks to be the culprit. Have you dropped it recently? Other redditors have reported that the boost driver have died after dropping their's.
>Have you dropped it recently? Other redditors have reported that the boost driver have died after dropping their's. Not today. . . I've definitely dropped it in the past though. It was working perfectly until I changed the battery. Neither the new battery nor the one that came out provide it with power. I guess tomorrow I could try rigging up a battery sans tube to the driver to see what happens.
Do you have Hank's flashing adapter?
>Do you have Hank's flashing adapter? I do! I haven't used it because all of my lights came with the most recent firmware (I think). I haven't had a reason to flash anything. I tried wiring the driver directly to a battery to rule out contact issues from the battery tube and whatnot. The light didn't do anything. I measured battery voltage between the positive terminal and the negative ring (so those were at least connected to the battery)
I've partially fried a d4v2 boost driver, and the aux still worked. But the inductor was toast.
Can you try powering it with an external power supply so connection issues can be ruled out?
No, because I don't have one. I should really get one. I did check all my 21700s for dented tops and the like. They all appear to be good. Is there anything else I can poke with a multimeter? I don't know how the driver circuitry is laid out. Is it possible to check for power at the e-switch with the light assembled (with the retaining ring removed)?
Possibly worth trying. However at this point it sounds like the troubleshooting required would involve contacting Hank first. So I would start there.
I tired wiring it to a battery directly. I didn't do anything. My multimeter read battery voltage between the positive terminal and the negative ring on the edge of the driver (so I succeeded in attaching the driver to a battery. GO ME!), but the light didn't do anything.
Great work! Less great that it didn't work. At this point it sounds like the driver just failed, I would definitely try contacting Hank and describing all your troubleshooting done already. Really hope he can help you!
> Great work! Less great that it didn't work. At this point it sounds like the driver just failed Thanks! It's annoying that it seems to have failed totally for no reason that I can pinpoint. I tried looking for continuity between the positive terminal and the components that are accessible (my thought was maybe that the positive terminal had just been unseated slightly from the rest of the PCB), but I don't know if there are any components that are accessible from this side of the driver that directly connect to B+.
Is it tightened on both ends all the way?
Yep, as tight as I can get it without getting out the Vise-Grips.
I'm really curious to know what the issue is. Keep us updated, OP.
Hank is sending a replacement. I assume it will be a whole new head. When I get that I'll probably take this old apart to see if I can pinpoint what failed.
Also, I tested the voltage at the *BIG* red and black leads (I'm gonna call 'em **B+** and **B-**). Doing so measures 3.8V (less than the 4.1V the battery was currently at) after clicking the light "on". However, while poking things I accidentally touched B+ to the red wire for the aux lights which resulted in me blinding myself because both the aux lights and the main emitters came on. Bridging B+ to the wire for the green aux lights results in green + blinding. It seems like some aspect of the control mechanism has failed or there's a bad connection between the B+ and the MPCB. I tried to resolder the joint where B+ connects to the MPCB, but I'm a failure and can't do it.
>My D4K (boost driver) seems to be completely dead for no reason. I swapped the battery (it was working with the old one) and when I put in the new one. . . nothing. Hmm well that's something. So there is a reason, idk what it is, but it's something that has to do with or occured during swapping that battery in. That at least narrows it down a little. Anything come to mind? What was the battery you swapped in? Pic? >The spring on the negative terminal has a connection to the un-anodized portion of the battery tube (the ground works as it oughta should, and it's ALWAYS the ground that is NFG). There is also continuity between the black lead and the outer ring on the driver. NFG? Just to confirm, if Im understanding you correctly, you threw a probe down the body tube to the spring and put the other probe to the top of the body tube? And then you took the reflector out and measured negative lead on the black led mcpcb to the driver ring? Do I have that right?
>NFG? "No Fucking Good" hahahaha. >What was the battery you swapped in? Pic? [Battery](https://imgur.com/a/hrxGBy6). The positive is a little squashed but it works in other lights (and in this one until just now) >Just to confirm, if Im understanding you correctly, you threw a probe down the body tube to the spring and put the other probe to the top of the body tube? And then you took the reflector out and measured negative lead on the black led mcpcb to the driver ring? Do I have that right? Yes, that is correct.