If a known good switch does fix the problem it would be worth checking my other post here: FW3A Troubleshooting / FAQ - #901 by contactcr
While ramping (any long press really) my switch would lose contact sometimes. It doesn’t sound exactly the same but if what shirnask suggests fixes it then it’s one thing you can check.
Every once in awhile mine with go out when reaching the top of ramp. I never tried reversing direction though. Cranking down the tail and head always fixed it. They never seemed loose but it always worked again so I assumed that was it.
Anyone here know if there is a 4-up spot optic in 20mm for fw3a? And where I can buy some?
So, update on misbehaving FW3A. I had not touched the light for a few weeks because I was frustrated with it. The symptoms are really as follows… When the light is acting up, it will turn on and ramp up to the top of the 7135 level and then stops putting out light. It does not ramp down, when clicked again it starts at the bottom of the ramp level (in my case moonlight) and ramps back up to where it quits again. To make it work for a while again, I have to remove the head and re-install it. I have swapped the tail switch with another properly working light and that light works like it should. While the other one still fails in the same way. I think my next step should be to reheat the board again and see if that fixes it. The return to moonlight level makes me think that something in the driver is rebooting the MCU, but I have no way to prove that.
I hadn’t used mine for a month or 2 and I left it without the battery inserted.
Today, when I inserted a new battery I got the confirmation flash but the light would not respond any further.
I removed the head and noticed that the retaining ring had become loose. Tightened it up and all is working again.
I have not used the flashlight for a month, because i am afraid of it’s strange behavior. Yesterday i played with it, the problem is still there.I disssasembled it, checked everyting:the driver, mcpcb, button, cleaned it, tighten everything. It’s not faint afterglow, it’s just glowing all time. So what the solution can be?
What emitter did you choose when purchasing the light?
If it’s Nichia, I’ve seen several Nichias behaving like that and it’s completely normal.
It would only be a problem if it drains the battery too fast. Have you tried measuring battery voltage over several days to see if goes down?
I think you can also measure the current drain from the tail cap area.
I ordered it with xp-l hi emitters, then swapped them with Samsung lh351d. The battery is Panasonic NCR18650B, almost new, just 10-15 circles I think.
I have a flashlight with lh351d at home.
Tonight I will check if I have the same “symptom” with the emitter.
I have an FW3T with SST-20, and the faint persistent glow is present on it. It is definitely NOT phosphor decay. It’s a very very very low illumination.
I don’t see it on a different FW3T with SST-20 or on the XP-L Hi 3D I have.
What is interesting is that the light this exhibits on is the one light that is very troublesome. I’ve struggled to get it to work consistently, and am not sure why. There’s something either subtly out of spec with this light, or something subtly wrong with it.
Just for fun, I swapped heads from one FW3T to another, and the glow follows the head, not the body/tail.
At least i am glad that i am not the only owner of not properly working fw3a.
I would suggest you both take a DMM and measure tail cap current drain. The MCU should turn off after about 5 seconds. You may have a leaky 7135 regulator or FET. Whether it is just a neat quirk or an actual battery draining problem depends on the current drain.
I have a meter and know how to use it, but measuring tail cap drain seems…not easy.
Either way, the fact that this light is also quirky in other ways suggests that perhaps there’s more going on.
The switch is sometimes unresponsive, sometimes requires more pressure to register a change, and occasionally does weird things. I’ve disassembled the tail, cleaned it, and reassembled it, making sure the switch is centered and the retaining ring is tight. I’ve also ensured the driver is centered and that retaining ring is tight.
Measuring drain is very simple. I used the head and a battery. I get 22 microamps. I did not even see the MCU stay on. I got the 2 blinks and the current instantly went to its lowest. I guess TK made the MCU go to sleep right away.
Did you test the switch separately? I can use the continuity buzzer on my meter and test the body/tube/tail assembly. If your switch is okay, you might be having a contact issue with the inner tube. I know these are sensitive to how tight they are and the order in which they are tightened. Tighten tail first, then head, etc… I can’t remember, but you tried different variations and still it’s not consistent?
I don’t know what else you could try. I guess contact the people you bought it from and see if they can send a new head or whole light. If you swap this glowing head to another of your FW3A, does the switch problem go away or follow the head as well?
If you put a good head on the funny acting light, do you still have switch problems.
I have 2 of these now. First one is fine. Second one will only ramp up to full power the moment you put a battery in. It would appear that the tailcap is the problem as I can swap that and replicate the fault on the working torch, and the defective light works fine with the known-good tailcap. Any ideas?
@VaKo, have you cranked the difficult tailcap down hard? Maybe with a pair of pliers and a strip of rubber to keep from marring the tailcap?
Cranked it down hard by hand, no change. I don’t think mechanically cranking it down will help because if I unscrew the head as it’s ramping up it will hold at the brightness level, then start ramping the moment the inner tube engages with the driver. The switch itself seems to be permanently jammed on.
@VaKo: One of my lights showed exactly this behavior until I cranked down the tailcap even harder. Now it works flawlessly. Also consider removing the pocket clip to make it easier to crank down further.
It’s easy to check tail button. Unscrew head and use DMM on bare threads and end of inner tube. It seems unlikely the button is stuck. It may be an issue of the inner tube shorted to ground. If you swapped just the tail cap, then maybe it’s just the switch is stuck.
It should not ramp to full power, 2000+ lumen. It should ramp to about 800 or lumen.