[POLL] Does your recent UT01 have ON / OFF problems?

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Jerommel
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[POLL] Does your recent UT01 have ON / OFF problems?
NO, it's fine.
63% (17 votes)
YES, it doesn't switch on after switching off.
37% (10 votes)
Total votes: 27

Looking for:

5” parabolic reflector (for recoil light)

Edited by: Jerommel on 11/10/2017 - 11:41
Jerommel
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A poll about the recent batch of Utorch UT01 many of us have bought.
Many of them won’t switch ON after switching OFF, unless you loosen and tighten the tail cap first (breaking the circuit).

It doesn’t seem to be a switch problem, but an electronic problem.

Looking for:

5” parabolic reflector (for recoil light)

Pete7874
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Just FYI, it seems that for some people the issue only manifests itself when using Li-Ion/14500 cells but not when using NiMH/AA cells, so please check operation on both cell types.

Tumbleweed48
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So far I’ve had one malfunctioning out of three, and the bad one is constantly getting better. It now works almost as flawlessly as the first two. I think mine has (had) crud in the switch – maybe a tiny shard of plastic or manufacturing residue that’s wearing away.

FWIW, and maybe a clue here, the drivers in mine are tight. I’ve picked at them with needle nose tweezers and a stout dental pick and I can’t get them to budge.

Streamer
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I have an earlier one…no problems at all… with any battery..

jf_smm
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I have 2 one does one doesn’t

ggf31416
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Mine, from previous group-buy, had a few occasional problems (for example it didn’t work for a bit after attempting to measure current with a DMM and once stopped working with 14500 and worked only with eneloops for about 15 minutes the fixed itself and sometimes needs a few tries while running), but mostly works. It’s an useful light but not one I would carry when I need reliability.

Sukoi
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Yeah, I got a lemon…

DENGOH
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Only happened to mine first day i got it. After, don’t encounter this issue anymore.
I bought it one month ago.

nydude
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I’ve got one on the way to me and one I ordered as a gift being delivered to the person. Guess we’ll see. :(.

Uname
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Well shoot, I ordered a few for stocking stuffers. I hope they aren’t lemons :/

kramer5150
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I bought my UT-01 Dec 5, 1216… is that recent enough for me to vote in the poll?

It has the condition described in the OP.

LightRider
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Tumbleweed48 wrote:
So far I’ve had one malfunctioning out of three, and the bad one is constantly getting better. It now works almost as flawlessly as the first two. I think mine has (had) crud in the switch – maybe a tiny shard of plastic or manufacturing residue that’s wearing away.

FWIW, and maybe a clue here, the drivers in mine are tight. I’ve picked at them with needle nose tweezers and a stout dental pick and I can’t get them to budge.

The switchs contacts ware in when used for a while. This changes the denouncing needed for the firmware to recognize a button press. This supports my theory posted in the review thread:

LightRider wrote:
Just a note: the problems with this light are not because of loose driver, bad contacts, or a bad switch. The switch however, is what manifests the problem. The problem is how firmware decodes the signal from the switch. When the light is off, something in the firmware tightens up the parameters that determine whether the button was pressed or not. Reason for this is unknown but I’ve wondered if it more “picky” with the handling of the signal from the switch to limit accidental turn ons. The firmware may not be broken through as it verywell may have worked with the switch used in testing(which may have not been actual physical switch at all). I say this because the light works fine with some switches and does not turn on at all with others. All my testing was done with the driver outside of the light so all other theories of mechanical problem from the host can be dismissed. Of course there is the normal one or two lights out there where this could be the problem.

I’ve read about all reported issues and all of them can be explained by my theory. Someone claimed my theory is in correct because their light started working when they straightened a twisted driver. However aligning the switch and pressing the button from a better direct angle changes the signal profile of the button press. It gives a better clean click so the driver reads the presses correctly.

Another claimed the problem is with the type of battery or because of different charge levels. These observations are probably correct but it doesn’t disprove my claims. Different voltages will also mess with the way the firmware views the signal from the switch. Either the voltage from the switch or the internal reference voltages of the MCU can be affected by different input voltages. This was confirmed by using a power supply to test the driver. Different voltages did affect the chance of the light turning on. Though, there wasn’t a general rule that deterermined what voltages did what. Each switch was different.

So, changing the switch may help defective drivers but not because the origional switch was “bad” it was instead not compatible with the firmware.

Good firmware design should take these factors into consideration. In fact, the designers of this light would have had to concider these things to some extent or the light wouldn’t work at all. The designers, however, must not have been thorough enough to acount for hardware variations.

This is my theory atleast. I admit, I am not fully qualified to make these statements. So maybe someone with a scope and a better understanding of firmware and switch press debouncing will test this theory further.

pc_light
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Mine did act up using NiMH cell (only.)

After the UT01 sits in the draw unsed for a couple of days, it would not turn on no matter how much I tightened or loosened the battery cap or wiggled the switch. But once I changed to 14500 cell it would work immediately. Then when I went back to the same/previous NiMH it would work normally again.

So now to avoid the issue entirely I simple leave 14500 in the light and never worry anymore.

Walk towards the light.

DENGOH
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I suspect it is battery length compatibility problem. Tighten up too much might cause switch contact problem.
I don’t think it is wear and tear of switch, since my light is new. And this poll is about recent UT01, not old one.

Swampus
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LightRider wrote:
…The problem is how firmware decodes the signal from the switch. When the light is off, something in the firmware tightens up the parameters that determine whether the button was pressed or not. Reason for this is unknown but I’ve wondered if it more “picky” with the handling of the signal from the switch to limit accidental turn ons….

Interesting. I wonder if the reason could be to limit the probability that static electricity will be interpreted as a signal input? I have a couple of older flashlights that are susceptible to this in the winter. Get them near a flannel shirt and they suddenly want to throw a disco flashlight rave party.

T-boon
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mine is a bad one too, so what could we do about it?

Tumbleweed48
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My fourth (and final) one arrived a couple of days ago, and it works fine. So far I’m “3 good & 1 not quite so good”.

The one that’s a bit quirky seems to be working pretty well, although this morning I swapped out a lithium primary and put in a freshly charged Eneloop. Nothing. Deader than John Cleese’ parrot.. Tightened/loosened a few times, nothing.

Swapped out the Eneloop and put in an Imedion NimH – worked perfectly. All modes. Lotsa light. Both are the exact same length, and both were recently off the charger. Go figure.

Swapped in a fresh (Costco/Kirkland) alkaline, and got L/M/H/H. Doesn’t surprise me, though, as I doubt the alky could surrender enough juice to feed the highest setting.

I have no 14500s to test them with; it’s just not a battery format that ever appealed to me.

I’ve figured out enough about its quirks that I’m still using it with pleasure. Kind of like me, it sort of works, and it works reliably for the duration of whatever cell is in it. When you change cells is when it acts up. I guess the three ‘perfect’ ones will go as gifts and the balky one will stay in my pocket.

To the guys that have bad ones, try this – when you put in a cell, wait 5 or 10 seconds, then try a slow press. Once mine starts working, it’s away to the races, and that trick has worked for me almost every time. Don’t ask me why! YMMV, of course.

O.K., this is a couple of hours later, and I have an addenda. I’ve been running the light on an Imedion NimH, steady on ‘low’, just to see how long it would run. Suddenly it just stopped cold.
No response to inputs, no ‘sag’ or dimming or flutter – just out.
Tested the Imedion at 1.21 v.
Put in a partially used lithium primary (Energizer Ultimate) and again it works perfectly.
I’m a patient man who likes a challenge as much as anybody, but……I’m stumped.

Jerommel
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T-boon wrote:
mine is a bad one too, so what could we do about it?

I don’t know…
I guess buyers should open a ticket on Gearbest.

Looking for:

5” parabolic reflector (for recoil light)

T-boon
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i just did that,
i dont know how they will react…
but what i do know is, i dont trust there reviwes, they never post my “bad” reviwes, only the goods.

btw, dose any one got the negative side of the eneloop damge from the spring?
like the battery tube is too short, and the spring is pressing too hard on the baterry.

Pete7874
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I am not seeing any damage on my NiMH cells, including one Eneloop.

What does your tail cap look like? Mine seems to have two springs, the inner one is kind of crooked… not sure if that’s normal…

Jerommel
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Yes, the batt. tube is very short.
Only AA and unprotected flat top 14500 fits actually…

Looking for:

5” parabolic reflector (for recoil light)

kramer5150
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No fit problems with my 2000mah eneloops or efest IMRs

westcoast
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Mine hasn’t arrived yet ( ordered Oct 25 ) but have been following the threads about this so will chime in when it does arrive! Unfortunately my 14500’s are protected so probably will only be able test Eneloops and Alkalines.

DENGOH
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westcoast wrote:
Mine hasn’t arrived yet ( ordered Oct 25 ) but have been following the threads about this so will chime in when it does arrive! Unfortunately my 14500’s are protected so probably will only be able test Eneloops and Alkalines.

Protected will be very tight. Don’t force it.
pieman7
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My UT01 switch has issues, but not exactly as what you described. Mine probably just needs a cleaning as I need to hit the button just right. Doesn’t matter if using AA or 14500.

Speadge
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pc_light wrote:
Mine did act up using NiMH cell (only.)

After the UT01 sits in the draw unsed for a couple of days, it would not turn on no matter how much I tightened or loosened the battery cap or wiggled the switch. But once I changed to 14500 cell it would work immediately. Then when I went back to the same/previous NiMH it would work normally again.

So now to avoid the issue entirely I simple leave 14500 in the light and never worry anymore.

I got my first UT01 today and I experienced exactly the same thing as you described.

At first I put in black eneloop NiMH cell. No matter what I did, it didn’t turn on. Then I tryed 14500 pkcell and voila, it works! Then I swapped this cell again with previously non working NiMH cell and now … it works!
Strange.