I noticed later model FW3 series lights have a retaining ring in the tailcap. This is to prevent the switch guts from falling out of the light if the tailcap is removed.
However, I noticed in my FW3T that this ring is VERY finicky.
Screw it in too tight and it seems to hold the switch PCB at a very slight angle resulting in poor connection and a malfunctioning light.
Screw it in too loose and it prevents the tailcap from screwing in all the way and the light does not work at all or malfunctions.
If you’re having problems with your light, one place to start is to remove the tailcap and try loosening and/or tightening that tailcap retaining ring until it works properly. Alternatively, you can simply remove the tailcap retaining ring. It isn’t necessary if you open the light from the front like you should.
That said, I don’t think this advice will help Richbuff. The behavior he reported (like press-and-hold for off) seems like it would require firmware reprogramming.
Nothing is glued in the FW3A. Tools shouldn’t be necessary. If you want to remove the tailcap, just grip it really hard and turn. If you’re having trouble getting enough grip try using a piece of rubber or grip tape for added grip.
Note also that malfunctions in the tailcap of the FW3A never result in a rattling tailcap. The inner switch tube can be misaligned or touching the wrong thing at the back without any rattle whatsoever.
Sometimes I wrap a rubber band around stuck parts to get a better grip without marring the finish. I’d bet the tail needs to be loosened or disassembled.
It’s only job is anti rotation. Some people don’t even use them. I don’t use it in my light. You might try a local hardware store. If no luck, maybe ebay.
I’m talking about the black o’ring for the water resistance. The one at the head is larger than the one at the tail. I can’t screw the tail cap enough.
Lumintop should send them as spare too. I’ll try at my local hardware store or online thanks!
edit: Now I’m thinking about put some silicone sealant. It will protect from water and prevent me from taking the tail cap out again.
And what function does this rubber ring perform? Moisture protection? I spun off the shank and pulled out the tube with the rubber ring, then when I put everything in place, I couldn ’t tighten the shank, the clip was almost free to rotate. I was only able to tighten the shank well after I removed this rubber ring. What did I do wrong?
Which o-ring are you refering to?
If the one on the clip, it is for anti rotation as mentioned before. It can prevent full tightening of the tail cap on certain lights.
Moisture protection comes from the black o-ring near the threads.
Wait are there two white O-rings? One on the clip, and one on the switch tube? I may have re-assembled one of my lights wrong. But the switch tube is anodized, so it doesn’t short.
From your picture, the left-most white ring is in the wrong place. Lift it out of the groove below the threads and slide it down over the black o-ring. It should be resting on the pocket clip, between the pocket clip and the black o-ring.
When you screw on the cap, the white o-ring presses against the clip and prevents it from rotating.
The second white o-ring in the right of the picture is meant to help keep the black inner tube centered and reduce the chance of a short between the inner tube and the switch. However, sometimes it can cause problems. If your light isn’t working right, you might try removing that o-ring completely and see if it works without it.