FW3A Troubleshooting / FAQ

I do have a question about the property of grease used in the threads. As I understand it, anodized aluminum is non-conductive. Electrical current and e-switch signals should be happening within the body via the tube, right? If so, why would I need a conductive grease on the anodized threads of its not meant to conduct any current? Wouldn’t plain lubrication and chemical stability be the priority?

I think the switch relies on the inner tube for its signals but the outer tube still is used to carry current for the driver.

Don’t use conductive lubricant in a flashlight. It’s a quick way to get shorts and leaks which are very difficult to get rid of, and can cause the light to stop functioning correctly.

The type of lubricant needed is dielectric / non-conductive.

It can also be important to make sure the lubricant does not cause the O-rings to dissolve. I forget which types do that, but two safe common types are Nyogel 760G and Super Lube PTFE. Both are dielectric and safe for O-rings. The latter is even food-grade; it’s basically Teflon gel.

Thank you all for trying to help
I connected the head to the battery, the way you described it, I got some sparks initially, smelled some smoke but nothing else. Light is not turning on and no blinks.Then I put on the outer tube, and nothing at all.

retaining rings seem to be tight enough, I didn’t take apart the head yet, I think I need a little different pliers. Dont want to damage the threads

Applying power to the head might cause a super tiny spark if your looking real close, but definitely not a big spark or cause smoke visually or by smell. It sounds like you have a bad driver.

One possible scenario is the person you lent it to might have put the battery in backwards and it damaged the driver. Maybe? IDK. I believe I’ve seen replacement drivers being sold. You’d need to be able to solder the 2 wires going to the LED’s, to swap it. Not too complicated.

One thing to try and loosen the driver retaining ring is to push on one notch with a tool like a tiny flat head screwdriver. Alternate sides. Most snap ring pliers are too big to reach in and grab it.

I see so FW3A doesn’t have reverse polarity protection. Will keep trying to take apart the head. and get a driver if nothing else.
Thank you again

I don’t know. I see one diode on the MCU power input. I guess that protects the MCU.

I tried digging around and can not find out for sure if has reverse polarity protection. Maybe someone who knows will comment. I am just trying to think of what could possibly happen that might cause the driver to stop working. They are pretty robust.

Another possible scenario might be the other person left it on turbo for too long and damaged one of the LEDs. A shorted led might try to pass current causing a spark when power is connected and a burning smell. Actually, anything that is shorted will do that. Ceramic capacitors used for filtering AC current do occasionally short. That is seen in Apple laptops all the time. In this FW3A driver I see at least three filtering caps. The FET or a 7135 chip could have also shorted, but that’s rare.

You should be able to check whether or not the LEDs are working by installing a battery in the light, removing the lens and using a jumper wire from the black negative connector on the mcpcb directly to a ground point in the head. When a battery is installed you have power going to the LED red wire all the time and the driver basically controls the current going to ground. So if you short it, you will get Turbo power to the leds. You just want to touch the wire super fast to see if the leds light up or not. You don’t want them to overheat.

Here is a basic diagram of a FET driver flashlight. You see how the black wire goes from the mcpcb to the driver? If you short that negative to ground you basically bypass the driver and the LEDs should come on full power. If you short the wire and the LEDs don’t come on, make sure you’re getting voltage on the red wire. If you put 3 to 4 volts across those LED wires it should work unless there is a problem with a burnt-out LED or a shorted out LED.

OK, I’ll defer to TK’s advice hereafter. It’s the conservative approach, no question about that.

I suppose an overheated lamp could vaporize the gel and redeposit it in bad places, on a high powered light.
Tho’ from experience, I’ve got a handful of Arc AAAs on which I’ve long ago cleaned up contact surfaces with [a tiny dab of] Nyogel and cured flickering due to dirty threads.

Note the black powder that accumulates on aluminum threads — it’s aluminum oxide, an insulator, that forms and is scraped off any time the threads are worked.
That’s what you want to remove. Wipe with a clean cloth if you don’t have the recommended lubricant to pick the stuff up.

Aluminum itelf reacts extremely fast with oxygen in the air, so produces a fresh oxide layer immediately when the thread contact moves.

I have an FW3A that turns off around mid-high while ramping up. The problem is intermittent. I can fix it by unscrewing the head and screwing it on again. My thought is a dry solder joint cutting off an FET channel, rather than a contact issue. What do you think?

I have the same problem with my FW3A, but I don't know what's causing it.

Try to tighten both retaining rings.

Both retaining rings (head and tail) are as tight as I can get them.

Try loosening the tailcap retaining ring slightly.

I found that on one of my FW3As I got a bad connection if I fully tightened the tailcap retaining ring. I think the ring caused the board with the switch to not sit quite flat and not get a good connection with the inner tube.

Yes; I did that for a bit, when I was having connection problems, and found it helped. At some point, I jammed the retaining ring in the tailcap and can’t budge it now. This switching off when ramping up is a different matter. I am wondering if it may cut off when the battery falls below a certain voltage; it worked fine last night between 4.0 and 4.1.

Mine at first did the same thing when ramping up. Tightening the tail cap and head always stopped it although I could not perceive them turning. Sounds like the inner tube is very touchy. For whatever reason mine has not done it in awhile.

It doesn’t sound related to the inner tube at all. The inner tube is only responsible for controlling the switch. When you have a complete loss of power as the amperage draw increases it points to something else. Perhaps really high resistance through the body connections or battery connections.

Middle age man, you’re using a flat top battery and not a button top, right? You by try cleaning the threads and battery connections.

Jason, I defer to your experience. Somehow mine stopped acting up after tightening the ends. Maybe the connection to the driver with the outer tube was bad? It stopped doing it totally by itself knock on wood.

I got that sort of thing, and loosening/tightening/cleaning fixed it. I blamed phantom button-clicks, momentary interruptions of the circuit.

I just want to say that maybe Teflon shouldn’t be referred to as food-grade. While it is arguably stable on pots and pans (until scratched), it shouldn’t be consumed.

If anyone wants my opinions about Dupont and Teflon in general…

Anyways, yes, electrical contacts should get dielectric grease - be they bulb sockets, flashlight threads, or whatever. A lot of times “Nyogel” is used as a generic recommendation; as mentioned in this thread, there are many types, and 760G is what you want for your flashlights.

It’s petroleum-based lubricants like vaseline that will stretch or dissolve rubber o-rings.