How to fix my Utorch S1 Mini?

My EDC started to fail recently.
Sometimes it would work OK but sometimes it wouldn’t turn on.
When I saw this the first time I thought it was LVP. It was not.
I tried cleaning electrical contacts - that didn’t help.
If it works it works - there are no issues with mode changes which rules out the switch.

What else should I diagnose?

Probably the strange white grounding wire is not grounding properly anymore. Have you opened it up already?

I had the same problem. The fault was indeed in the wire that is connected to ground. It is necessary to remove the lens and check the ground wire to the lamp housing.

Just checked: the wires seem fine, at least where it’s easier to see them, at the MCPCB side.

The ground wire is soldered to a thin screw. it is screwed into the flashlight housing under the lens. At my flashlight, the screw had bad contact with the flashlight housing.

Mine also had a good solder connection, but the screw was loose. I cleaned all the solder off the screw head then tightened it up with a mini screwdriver. Resoldered the white wire and it’s now perfect.

Mine won’t consistently give me the high mode. Sometimes it does, sometimes it doesn’t, even with a fully charged battery.

I wonder if this could be related to that screw being loose?

Could it be the Lumintop battery with the built in micro USB charger?

If I start in ML and then advance upward, I get all the modes.

If I go to strobe, turn the light off, then turn it back on, I get all of the modes.

It’s behaved this way since I got the light a few months ago.

Mine is flaky as well. Give it a whack in the right spot and it comes good.

The screw is not loose in my case. But the light is working again, so my troubleshooting attempts need to be delayed…