FW3A Turns On and Becomes Stuck When Tail and Head Tightened

Hello,

I’ve had the FW3A for about a month now, and have really enjoyed it. Gotten to know the UI pretty well.
However, I am experiencing a strange behavior that just seemed to start happening. I had just taken the battery off the charger, and inserted it into the flashlight. When I tightened down both tail and head caps, my light turned on, ran through my set power steps, and then got stuck on my highest step. Pressing the tailswitch once this occurred did nothing - I had to unscrew the flashlight to turn it off. This is repeatable, and I have been able to make this happen again and again. Sometimes it will go from high to low. If I get the perfect balance of tightness on both caps, the light seems to function normally. But if either cap is too tight or too loose, the flashlight either does not work, or does the aforementioned cycle on and get stuck procedure.

I am using the same Samsung 30Q I have been using for a month now.

What is going on here? More importantly, what should I do about this?

Here is a video of this issue.

Apologies about the sirens in the background.

Thanks for reading.

Read through this:

FW3A Troubleshooting / FAQ

Did you remove the tailcap? (Don’t!)

Followups to the Troubleshooting thread will be easier for others to find later.

Thanks, I’ll read through that and crosspost in it once a solution is found.

Regarding the tailcap - I removed it when I first got it, and ensured nothing fell out. In the newer revisions of this light, I believe there are no loose parts in the tailcap, making the “do not remove the tailcap” warning not as important as in previous iterations where it was possible to lose small parts.

However, the flashlight behaved completely normally for about a month now, meaning my initial tailcap removal was not the cause of this issue.
I did loosen the tailcap about a quarter turn today before inserting the battery, then tightened it down (which, coincidentally, is what the troubleshooting thread says to do). I’m guessing this has something to do with it.

Yup.

Remove the head. Then tighten the tailcap. Then insert a battery and tighten the head.

Yep, no dice. Issue still occurs.
The driver retaining ring is also tight.
Any other ideas?

“subscribed” as I have the same issue from day one with my stonewashed titanium fw3a, second one (regular gray alum) works fine. I still did not have time to investigate what is causing it. Nothing obvious, I tried different orders of tightening tail/head with no success.

I wish I had a constructive comment. Mine did the same thing. It was intermittently yet repeatably doing what you describe. I thought I had it fixed by tightening it down as directed, and I set it on my counter. I came back in 15 minutes or so, and the light was on max and so hot that I got second degree burns on my fingers where I tried to grab it. I immediately dropped it, and I had to grab it with tongs and dunk it in water until it cooled enough to unscrew as the power button did nothing. It was so hot it actually melted one of the LED’s off of the driver.

I loved the light, but this is a dangerous flaw and I haven’t seen a solution. My tail was cranked down tight, but still displayed the problem. Here is a video I made, you can see as soon as I tighten the head the light immediately ramps up, but it gets washed out.

The issue was not present when the light was brand new, and didn’t start happening until I owned the light about a month.

Metal shavings?

https://www.reddit.com/r/flashlight/comments/e3svp6/fixed_fw3a_rebootingwhileramping_issue/

Could be because of the Button Top cell you’re using —- a couple of mine won’t work at all with button tops —— it appears the cell is too long and pushing the button when you tighten up the head all the way—try a Flat Top cell

I can “fix” this issue when I remove the clip, tighten the tail first with standard force, not extra tight, then tighten the head same way. It works this way, but I want to investigate it more, as I don’t trust this not to turn on accidentally and burn something.

In my case it’s not metal shavings.

Same here, only had it for a week now, I removed the tail cap to get rid of the clip and it all went wrong, after a few tries unscrewing the top and tail cap it started working normally, seems very odd you are told not to remove the tail cap, mine came with this (which I admit I did not look at until yesterday) :)

Well, looks like I’ve got an FW3A for sale now. Condition is as described in OP - just pay shipping.
Very disappointing.
Edit: sold

What led choice is it and where are you located?

Cree XPL HI 3D NW, and Eastern US
Edit: sold

My polished Titanium FW3T did this after I swapped in a different optic.

The problem: When I screwed in the new optic fully there was significant pressure on the star. Either the solder job on the star was defective or the heat on turbo got so hot it melted the solder under the star. This caused solder under one of the LEDs to bridge the negative pad and the ground pad.

The result: The driver was bypassed completely. Screwing in the light enough to make a battery connection caused it to turn on at max turbo. And because the light was in direct drive and bypassing the driver, there was no thermal rampdown protection.

The solution: I removed the star and reflowed all the LEDS, double-checking for excess solder under each one. Then I reinstalled the star with fresh thermal grease underneath. This completely fixed the problem and the light now works fine.

My FW3T Ti-Cu also has a defective connection around the inner tube. It works fine using a flat top 18650 such as the VTC5. But if I try putting in an older and slightly longer button top 35A, the light ramps up as soon as it is plugged in. It’s not bypassing the driver, but it’s clear that the switch connection is bridging to ground where it shouldn’t. Could probably fix with kapton tape around the bottom of the inner tube.

Yeh, I’m imagining storing it in a bucket of water when I’m not carrying it. It gave me bad dreams.

I keep mine on top of a bucket of ice in the freezer. Easy to grab when I need it, but when it melts down it safely encases itself in ice within a few minutes. Only takes a few hours to fetch when that happens. Very practical!

Hmm, this may be exactly what happened because the temp sensor was calibrated and set to 45, and it obviously did nothing. Any tutorials out there on reflowing leds? Might as well try on this light as otherwise it’s a $50 paper weight.

These things are junk.
Dangerous junk.

Any flashlight that you have to loosen the head, then the tail then remove the battery to charge it and repeat the process and then the flashlight still gets stuck on high when it feels like it with no way to get it to shut off other than burning yourself to unscrew both ends is just nuts.
TOTAL FAIL

Any USA dealer that sells these things are really asking for a good winnable lawsuit against them.

Tell me of one other electrical item that you have bought in the last 10 years that has this many serious and dangerous faults?
I know of none other than those hoverboard things and they got run out of the marketplace real quick.
Never bought any of those.

Definitely not a Light for the Novice User