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

You can see the archived poll results on the Wayback Machine:

https://web.archive.org/web/20221220093741/https://budgetlightforum.com/t/-/72790

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.

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.

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.

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

I have 2 one does one doesn’t

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.

Yeah, I got a lemon…

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

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. :(.

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

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.

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:

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 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.

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.

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

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.

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

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.