Nice patmurris ! I use the IMR 14500 ButtonTop / WindyFire. Great fitment !
I had repaired 2 UT01 switches with one from Mouser, they worked with new switch again,
The original switch is not reliable, sometimes it works when pushed in different angle, but normal operation is not really possible when the switch develops a problem
For 14500 I advise adding a solder blob or brass button on top of the battery
If you are able to reflow things with hot air its a 15minutes repair
link to buy the switch ?
i need replace 4 of my lights too >.<
I don’t believe the problem is the switch though changing the switch can solve it. I believe the problem is how the MCU reads the signal from the switch. I just did some thorough testing on my unit and replacing the switch does not always solve the problem. In fact the problem can remain even while manually shorting the switch input by tapping two wires together. It also will not work with those really flat switches that are held together by some sort of thin plastic/tape. Don’t know how to describe them. There were some other switches that did not work as well. However, some switches work every time without a hitch. I also tested the “misfiring” ut01 switch on another driver and it works fine. It confused me for half a day at least. 
In general, low resistance switches with a sharp “click”, worked the best. Of course this is just one driver I have tested and others will have to check for themselves but I do think this can explain some of the problems others are having as well.
For my light, I can’t power cycle it ON-OFF-ON-OFF, without doing this…. ON-OFF-Loosen/tighten tailcap-ON-OFF-Loosen/tighten tailcap-ON-OFF-Loosen/tighten tailcap. This ONLY occurs with a 14500 cell. Eneloop works 100% perfectly.
Do you think this light is die-ing a slow death? Have you guys seen cases where a light behaves as I have described and then suddenly without warning stops working entirely?
In an earlier posts in this thread, I mentioned that my first two UT01s worked perfectly while a third does not. I have an update to that. I decided to keep the two ‘good’ ones for gifts, and struggle with the balky one myself.
Oddly enough, the more I used it, the better it worked. To begin with, it was reluctant to come on, reluctant to turn off or to change modes….it would ‘stick’ in low and need to have the tail cap loosened to regain any function. In one of its more co-operative moments, I did manage to run the programming cycle, which it remembered… (The driver board in this one is stuck tight, and I can neither budge it nor get the nose cap off; I’ve applied force to the point of fearing damage.)
After a couple of days of relentless and frustrated clicking it began working more and more consistently. Now, while still on its first lithium primary, it works as well as the other two. There remains a sense of something not being right in the switch - a feeling of two clicks ‘on the way down’ for lack of a better explanation - but it’s much better than before and it obeys all inputs without hesitation.
While I don’t doubt there might be a variety of problems with these lights, mine appears to have a mechanical issue in the switch which is somehow rectifying itself through repeated use. I’ll continue to use it. Mercilessly.
Thanks for the report, tumbleweed48.
What lightrider has described sounds like a combination of electrical, mechanical and programming issues, with the switch being a locus of electrical and mechanical issues. Your description isn’t inconsistent with that.
From your description, I see another possible component of the problem, instead of or in addition to an issue with the switch that may remediating with use. You say you are still using the same lithium primary with this light. That means that the supply voltage is declining, which could also be playing a role in the way the MCU “observes” the signal from the switch.
This is consistent with some of my earlier, crude, operations, that the problem seems to have some relationship to the type of cell I’m using, and, with a given cell, may change over the discharge of the cell.
I just looked at this more closely. With an unprotected 14500, a couple days off the charger, I’d say the chance of any click being registered, by turning on the light, after the first turn-on after power-cycling the light, is about 1-2. With a Lada NiMH a few days off the charger, the success rate is closer to 10-20, and I just had a run of 100% success, until I removed the cell and tried again with the 14500, which again only had a 1-2% success rate.
In all cases, once the light is “on” ~100% of clicks are registered for switching intensities/modes, and turning off the light.
FWIW, I’ve been able to run through the programming cycle and then disable programming mode and have the changes stick. This works even if I have to power cycle the light, do a long press to enable programming mode, power cycle, click on and into programming mode, update the settings, turn the light off, and then power-cycle it again before doing a final 10s press to disable the programming mode. Or, to put it another way, the last state of the programming ritual seems to persist even if the battery is removed.
I haven’t found that going through the programming cycle makes any difference in turn-on efficacy.
LightRider, do you have either an actual O-scope trace, or a working hypothesis in your head of how the switch signal looks with a problematic switch, vs a good one?
How much of the circuit do you understand? I wonder if perhaps the addition of decoupling capacitance or a small RC filter, somewhere easily accessible could make the system more robust with the typical range of manufacturing, power supply, thermal and wear tolerances.
Pardon me if the above question is silly; I ask based on a rudimentary understanding of electronics and firmware.
I do not have an oscope. My observations were a result of swapping six different types of switches and testing it through different voltages with each switch. It was clear that each switc carried over its same functionality if swapped out and swapped back in. Right now I have a switch that the MCU is 100% satisfied with as aposed to the stock switch that was less than 30% successful. And another switch that I could only get to work a couple of times at most.
My knowledge of circuit s sounds to be about the same as yours. I was wondering how same ting. Capacitance and voltage level could have a huge impact on the way the switchs clicks are read. I would bet that the firmware was tested on better or maybe just different components than the drivers production components. I would not have the knowledge or equipment to test this stuff. I guess trial an error. I could hook up the bad switch an add/drain capacitance at the switch pin. By the way, capacitance could be draining with a power lockout and thus allowing the switch to function again.
There is something whacked in the software.
If it won’t turn back on with the 4.2 battery after having been on, just by twisting the head twice breaking contact and then Boom comes on fine until it is turned off again.
It is acting like an electronic lockout.
Doesn’t do it as bad with 1.2 Ni-Mh but still acts wonky.
What is the sequence for lockout on some of the other Manker flashlights?
Maybe software is the same?
I am just treating as a lockout feature for now
Later,
Keith
Yeah me too… mandatory lock-out. So far this is the only thing wrong with it.
Sigh…
Got mine in today, only tried with Eneloop, same lock out problem…
Switch seems to be good though, but once turned off it won’t come back on unless i unscrew and tighten the tailcap first…
:weary: this sucks…
(edit)
Hmm… sometimes it does turn on, once every 20 clicks on average…
Maybe it is the switch afteral…
Very vague problem…
Good idea, that is, if everyone who bought one this time will vote.
I’ll start a poll.
So what do guys do with all these malfunctioning ut01 lights? Do you reach out to GearBest and demand a refund?
Try this;
Smack the flashlight (tail down) fairly hard onto a solid surface like you’re smacking a pack of Cigarettes and see if it doesn’t come right back on with a click after doing this.
The freakin driver assembly is free to move around, bad design.
I tried switching the tailcap and batt tube from my good one, no difference, problem is in the head.
Later,
Muto
I’m not going through the hassle of video, 14 PM’s and emails of bad translation and form letters for a $10 flashlight that works fine once you know what it needs to come on. It works fine once it’s on.
The older version I have does not have this problem, Progress they say?
Poll here:
Please vote to get an idea how many % is bad.
I may well open a ticket, yes.
See what solution they can offer.
I mean, a bargain is nice, but not when the product is faulty (obviously).
Just got mine today. So far, it appears to have no issue on either NiMH or Li-Ion cell, knock on wood.
However, visually, I don’t think this thing delivers 800 lm. Based on the results of the ceilingbounce app in my make-shift integrating sphere, lumen output is about the same as my JetBeam Jet-1 MK, which claims 480 lm on high.