TK's Emisar D4 review

@Cpeng so I guess I’ll just keep using it as is for now if it’s not going to hurt the light overall. How hard is an emitter swap to do? I guess if another goes out I could always Try to swap them out for some lower temperature emitters.

@nastynate : Honestly I haven’t ever done an emitter swap, or reflowed an LED (but I have soldered surface mount and through hole many times). But I would first try to reflow the LED to the board with hot air or a hot plate. A hot plate would relfow all 4 leds at once but if you have flux I think it will work fine. You would have to remove the MCPCB from the light by de-soldering the wires with an iron. There are a lot of you tube videos that show this. If it was me I would keep using it, and buy another one. Honestly its cheaper for me to buy another flash light then to get all the tools together to fix my own.

Do you have basic soldering skills? If so, emitter swapping is fairly easy.

I use the following method:

  1. Desolder driver wires to the star.
  2. Remove star from light (I find a small dental pick like tool is handy for reaching under stars to lever them up).
  3. Place star in wooden clothespin. The edge of the star should be held by the pin. Do not put it over the LEDs.
  4. Place wooden clothespin with star in small table vise.
  5. Apply 40w soldering iron to bottom of star or if you have it the hot air gun from a hot air reflow station. Keep it there until star is hot enough to melt solder on the upper side. If no luck you may need to clean your solder tip or use a fatter tip.
  6. Use tweezers to gently lift up LED while holding iron to underside of star with other hand.
  7. For the non-working LED: I recommend applying a bit of fresh solder paste with a toothpick. Maybe it just doesn’t have enough and needs to be reflowed.
  8. Cool the star. I do this by removing the star from the wooden clothesclip and placing it on the small anvil built into my table vise. This is enough to make the star safe to touch with fingers in less than a minute.
  9. After reflow run a small handfile over the bottom of the star to smooth out any solder residue left by the iron.
  10. Use Q-Tip and clean off all thermal paste under the star and on the shelf in the head.
  11. Apply layer of fresh thermal paste. I use Arctic Silver 5.
  12. Place star in light and reassemble.

I like to test reflows before putting them back in the light. I have a small 1xAA battery carrier I got from Radio Shack years ago with a wire coming out of each end. I put a 14500 inside and touch the wires to the contact pads of the star briefly to check that everything lights up as it is supposed to. In your case, I recommend testing the star after the reflow to make sure all 4 light up. If the dim LED still does not light up fully, you should probably replace that LED.

Make sure to go slowly and methodically. Don’t try to rush it, especially your first time.

Entire process to reflow all 4 LEDs and replace with different ones in the Emisar D4 shouldn’t take more than half an hour even going slowly.

Check the emitter with the multimeter set to continuity, observing polarity, and the meter will run enough current through the pads to make the emitter light up dimly. The least destructive way to test it if there’s a short circuit…

I have dropped this light on the cement a few times and the bezel looks like an octagon
I have tried to smooth it out but it is not good enough to hold a seal.
I looked on the int outdoors website and saw spare lens and optics, but no bezel.
Has anyone ever tried to buy a spare?
Might go for lens and optics too. They both came off the last time I dropped it. Maybe a magnet installed in my hand would help.

The titanium in your hand is not magnetic, though the plate in my head picks up satellite tv

Ouch!

If your bezel is bashed up from being dropped, your best bet might be to try to bend it back into place. Maybe with pliers when it is removed from the light.

Alternatively, perhaps you can buy the Titanium D4 and install its bezel in your aluminum D4. Titanium is tougher and should be more resistant to abuse.

Sure I bent it back, but it is thin and bound to happen again. I woul buy the titanium bezel if sold separate or steel if an option, but not an entire light. I cannot be the only one that abuses their light can I?

Shoot Hank an email. Got mine replaced when I bought another light from him even though I did not buy my second D4 from him. Neal refused to help so gained a lot of respect for Hank and will never buy from Neal’s Gadgets again.

Might be prudent to learn not to drop your tools, I’d ask Hank about purchasing a Ti bezel and then I’ definitely be more careful about it falling.

My Dad taught me long ago to consider what it meant to me if something could fall and be broken, place it as low as possible if falling was a risk, if it’s on the ground it can’t fall! Not having the money to replace something I got good at not letting it get broken in the first place, accidents do happen of course. I have never stuck my phone in my back pocket, for example. My daughter has ruined way too many phones, sitting on them or dropping them.

Lanyards , if you just can’t avoid droppage, and this may mean your light choices are limited to lights with a good lanyard… or at the bare minimum lights with a robust build.

(The IRA Night Watch is built like a tank with a very thick SS bezel, for example)

The bezel O-ring is very thin, so the seal can be easily broken. My white D4 didn’t even keep water out when it was new; it leaked through the bezel (not the lens). I fixed it by swapping the thin O-ring for one of the spares included that are designed for the body. It’s much thicker and a tight fit, but you might want to give it a go; it could be wide enough to seal the uneven surface of a damaged bezel.

I diassembled my D4 to flash new firmware, now it dims when i turn it off. I think the circuit is short somewhere, what is the best possible cause?

Update: after some test with multimeter, i found that the flashlight aluminium body was short circuit with the negative of mcpcb. I also found that the noctigon mcpcb is made of a thin top layer of copper to conduct electricity, and the thick copper bottom layer. My screws somehow connect the top and bottom layers. But the screws are also used in original D4, why does it cause problems now?

The flashlight Mod God’s yankin your chain… they’re funny that way.

I agree with everyone that suggested talking to Hank. He’s astoundingly accommodating to everything and anything.

Is there any option to configure the temperature sensor as in Anduril? My D4 marks about 15º more than the ambient temperature

Nope, not without changing the firmware. RampingIOS V2 doesn’t have a sensor calibration function. RampingIOS V3 does though, and so does Anduril.

Did you lose the insulating washers? There should be two washers per screw, a metal one and an insulating one. The insulating one goes against the mcpcb, and the metal one on top against the screw.

Thanks TK. Anduril works good on D4? time ago I read a thread where it was said that the temperature sensor of Anduril didn’t work well in D4.

Works very well on the D4. I have Anduril running on three D4’s. As long as you set temp limit at a fairly conservative level (mine are at 45C-50C). Then it never gets too hot.

Conversely, I have Anduril on all my D4’s, and I set the temp to maximum and have no trouble. TK fixed the old thermal problems, or at least put in a workaround. It’s called something like “THERM HARD DROP” I can’t remember exactly. But it drops the output down to a sane level after the temp starts climbing too high. Works real well, if maybe a little overzealous. So if you want extended turbo times, you’ll need to set the maximum temp higher. In my experience anyway.