Not sure what’s wrong with it. I tested that firmware version, but only with aluminum. I don’t have a titanium model to test.
Results looked like this:
I’m guessing the titanium and copper version might ramp down a little slower since copper takes longer to get thermally saturated, but it may end up stabilizing at a lower point since titanium isn’t very good at shedding heat.
Anyway, whatever it’s doing, your KR4 behaves in a way I haven’t seen before. Overheating suggests it’s failing to regulate down for some reason… and then the shutoff, delay, and boot-up blink suggest power is getting interrupted while it’s hot. But I don’t know why or how.
The closest issues I’ve seen are:
Some K1 12V drivers have blinked off and on while hot, if the boost chip isn’t heat sinked quite right or if the thermal limit is set too high. This is because of the boost chip’s built-in protection shutting it off.
I have a particular 26650 battery which makes my D4S runtime tests go crazy. The battery overheats and then causes output to jump around wildly.
I’m not sure if the KR4 has any chips onboard which would cut power when hot… I haven’t managed to cause that to happen even if I keep activating turbo manually to keep output higher than it should be.
Thanks for your input, here’s some additional information.
Ok, so another quirk happened, the light refused to change between stepped & ramped output modes and would not reset via the 13H method, I had to use the tailcap version to reset it after a couple of attempts.
I did some runtime tests at various outputs after resetting the light to factory settings.
It does seem to ramp down but then just cuts off within a minute.
Hank has replied to my email and asked me to return the light which I will do.
Bummer, always happens when you REALLY are looking forward to something - I’m sure Hank will sort it though, he is for sure one of the ‘good’ guys out there.
A question for any new KR4 Ti owners out there. Does yours have a slight gap between the copper head and body tube? As shown in the photo, mine is tightened down all the way and still has a gap. The titanium can be seen reflecting light inside the gap. I’ve tried without a battery and it’s the same. There seems to be less of a gap when using a 18350 tube, but still there. I wonder if the light’s tolerances were created with anodized aluminum and not compensated for the non-coated copper? It doesn’t affect the function of the light, but it might trap debris in the gap. I might end up 3D printing a gasket to bridge the area.
My brand new D4V2 CuZn E21A 2200K has a weird issue.
Sometimes, but not always, main emitters stay on even after I turn off the flashlight. They are at a level somewhat higher than moonlight. I don’t know how to trigger this issue yet. It happened on its own after I did not use the flashlight for a few minutes. Once it happens, simply using the flashlight or disconnecting the battery does not make this issue go away. It does somehow go away on its own.
I have seen it both start and stop happening while I was not using the flashlight or pressing the button. It was turned off.
Reset does not fix it.
It happens regardless of the level the flashlight was ramped to before it was turned off.
It happens with all aux led settings.
Even using manual lockout and turning the tailcap, pressing the button to make sure battery was disconnected, and then undoing the lockout doesn’t make it go away.
Everything else seems to work fine.
Hm, dang. Above issues CRX and lightdecay are experiencing made me check my “old” D4V2 Ti and Br and both after some time have a glitch like lightdecay explained.
Just to clarify, the issue is that main emitters never turn off unless battery power is disconnected, but otherwise the flashlight works fine. They are brighter than the lowest possible moonlight level is, but not very bright.
Maybe Hank just ran out of 2200K E21A emitters. Maybe he just purchased a small number of them expecting sales to be very small. In any event, I’m very happy I purchased mine when I did. I love the 2200K KR-4.
My flashlight is working fine right now. Due to intermittent nature of the problem it is most likely not firmware related. I think it could be a minor short. Does anyone know if lube conducts electricity? I wonder if I should try cleaning the driver with isopropyl alcohol.
It sounds like the lights may have developed a leak.
When power is connected, it normally has two paths it can use to reach the main LEDs — the low power channel, and the high power channel. Normally they both block power and prevent it from flowing while the light is in “off” mode. However, either one of those could potentially become a bit leaky over time due to wear and tear, making it so they don’t fully stop the flow.
Or a third path could develop, in a variety of ways. Some of these possibilities can be resolved by cleaning the inside of the light, while others are more difficult. Cleaning it is generally a good first step, though. Ideally, clean it with dry methods first, to remove as much gunk as possible, then test it… and if it still has issues, try it with isopropyl alcohol next. Usually it’s not good to start with a wet method, because that can carry conductive dust deeper into the light and cause a leak.
Furthering TK’s theory of a “leak”… I could see this maybe happening if the gate pin of the FET was floating (due to PWM stopping when the flashlight is turned off). The only Emisar driver I have sitting around is my original D1S driver and I see it has a gate pull-down resistor, so it shouldn’t be able to float. Do these new(?) drivers have gate pull-downs? Or is it possible that it got damaged (or not soldered properly)?
