Just saw video and wasn't reading above posts.
Light flickers on low and won't turn on properly due to bad solder contacts on MCPCB.
It was the same case on mine but i solder everything again and now it's perfect.
Also helps if you loosen the bezel a bit
On the one hand it is certainly good for consumers when a reviewer highlights QC issues in such a brazen way. It does not surprise me that Lumintop asked you to take it down, however I am pleasantly surprised that you refused and made their request public.
Lets be real for a second - many consumers received FWxx lights with similar issues so finally we have a video representative of the experience of many people. In fact many Chinese flashlights - Astrolux etc - have terrible QC issues at launch and yet this is rarely disclosed in reviews. Some reviewers are very fond of their stream of free flashlights and affiliate revenue and do not want to bite the hand that feeds them.
On the other hand the name calling and hostility detract from whatever good you are doing. I suggest to take a step back and reappraise your approach.
I just tried a bunch of 14500 in my 219c version, Shockli, Vapcell, Klarus, Nitecore, Sofirn, and AW, protected and unprotected, button and flat top, and they all worked. It does sound like a contact issue.
I am sorry that you got a bad working sample, The_Flashaholic. 
As far as I can tell from the experience of my 2 samples, the batteries you used are not the issue as they don’t seem “too long”, so, as many others mentioned before, it is a driver or contact problem, which I hope you can solve in some way (even getting a new one).
Also, and to refer to The Auditor post above, only my 2 unprotected button top Vapcell batteries didn’t work, as they probably compress the driver spring too much or constrain the inner contacts in a way that the flashlight didn’t turn ON. Maybe the inner tube is the issue, I don’t know.
I would also like to say that you did an honest review concerning the flashlight you got (as with other lights), and if it is not working well, you portrayed it that way. That doesn’t mean that you are the only honest reviewer, it means you make honest reviews about the flashlight samples you get, either they are damaged, malfunctioning or not.
I did an honest review about my 2 FWAA working samples (1 bought, 1 offered), and I expressed what I like and dislike about them, even if it isn’t the same as you or others like or not.
I guess that doesn’t make me a dishonest reviewer, right? I do have less means to make a complete review with numbers, etc, but that doesn’t mean I (or anyone else in the same conditions) am dishonest! I don’t feel personally touched by your words, but I wanted to point out this aspect to level out some ideas. 
Again, I hope you can solve that issue and get one or more functional pieces.
And I hope you can make a full review, as you normally do, when you get that working sample(s). The way you portray how the lights work and their range in open spaces is quite unique and useful to see what a flashlight does: illuminate.
I’ll give it a go thanks.
Lumintop are asking me to remove the 2 reviews again this morning saying they’ll damage the brand
What is the point of reviewing?
I’ve blocked Victor Zhou and will never review a Lumintop flashlight sent directly by them again.
I didn’t appreciate the slight against the whole forum but I can certainly respect you for sticking to your guns against lumintop
I just tried a Wuben protected and a Skilhunt protected. Neither fit. The Skilhunt is 52.8mm in length and the Wuben is a couple of mm longer.
Cheers mate.
Don’t laugh, this is probably going to be one of the most valuable threads on BLF. I like that we finally are seeing reviews that are not only honest but bring out the real negative characteristics in lights and in companies. I am real tired of seeing the overwhelmingly positive reviews that talk about foolish things like “well greased threads” and how the “style and finish is nice.”
As others have mentioned, thanks for the integrity and the honest review. I just need to remind everyone that name-calling and personal attacks are completely off limits on this forum. Please go back and edit or delete your posts if they have anything that goes against these rules:
On mine loosening the head a couple of turns or taking the TIR out and going mule/commando mode removes pressure on the MCPCB and allows the light to be in an off state.
My favorite burger lately is the onion smash burger.
jon_slider, I made some new tests and put them here regarding the batteries I mentioned that didn’t work.
Take a look. They worked now, maybe due to less tension on springs, but I still wouldn’t use them in this flashlight.
There’s a thread on TLF where one user was able to fix this problem by recentering the driver PCB.
Of course, such problems shouldn’t be there, and one other manufacturer seems to not have them with his lights using an inner signal tube. A few dollars more expensive, but a whole different class quality-wise. So thanks for the review . And for this easter egg: Not again, please.
This is also expected behavior when you have a short to ground caused either by bridging solder between the negative and heatsink pad under one of the leds, or when you have the negative driver wire touching the side of the star which also creates a bridge from negative to ground.
In both cases, you get connection that bypasses the driver through the star. But in order to have a short, the star must then have an electrical connection into the head of the light. Without pressure on the star, the star tends to ride up on its thermal paste and not create a good electrical connection. But when you apply pressure to the star by screwing in the bezel completely the star is pressed through the paste and an electrical connection is achieved.
I haven’t tried removing the star in the FWAA to see if the shelf is anodized or not, but even if so electrical connection could still be achieved by the star touching the head of the screw that is installed to prevent the star rotating during assembly. The result is the same… pressure is needed to create the connection.
Had this same problem in a DQG Tiny III I modded a few weeks ago.
Firelight2, here is a photo of the shelf, originally posted - along with other photos - by id30209 here: What did you mod today? - #9942 by id30209
Thanks Mascaratum.
From that picture it looks like the shelf is anodized. The white stuff all over it is thermal paste. You can tell from the picture that the white is not bare aluminum by looking at a bit of the grey anodization on the shelf to the upper right of the screw.
It appears The_Flashaholic is getting a short to ground either under one of the LEDs or where the negative driver wire passes through the hole in the star. When the star is firmly in place, the edge of the star presses into the screw in the top of the picture. That screw passes through the anodization and creates a short to ground bypassing the driver.
Most modders can probably fix this without needing to return the light by doing the following steps:
I’m surprised Lumintop contact anyone, any time I message them it hits a black hole.
I had an ODL20C that wouldn’t charge. They’re charging outrageous prices for the lights on their website (anywhere else is cheaper)
People crap on Fireflies, but they’re better than Lumintop any time.
The brand deserves to be damaged. They have made some nice lights but over the last couple of years and especially lately I’ve gradually lost any respect I once had for Lumintop as a company. It seems they themselves are doing more damage to their brand then any reviewer.
I like small and powerful lights even with their limitations but I held off buying the FWAA until it’s offered by a reliable seller. With quality issues coming to light I might be waiting longer if I buy it at all.
I have eight Lumintop lights, no problems. Three FW21a Pro vn, FW21a Pro 3 x 90.2 vn, two BLF GT94, FW3a W2 vn, and FW4a W2 vn. No problems, all good.
Honest reviews by The_Flashaholic: I look forward to his reviews; it has been that way for more than a few years. About four years ago, when I was super excited about collecting Acebeam lights, he did a bunch of positive reviews on various Imalent lights. I waited until the Imalent R90TS came out, and then I got excited about Imalent lights, but then he began pointing out issues with Imalent lights. My five Imalent lights are all good, except the MS18 battery pack takes a long time to fully charge. So, I plug it in, deal with surviving on the surface of this earth, and when I can catch my breath, the pack is charged. I can't complain. So many things on earth are much worse.
I have had great results with the 49 performance lights that I have gotten from Acebeam, Imalent, Lumintop and many other makers of routine/nice quality lights. I should be happy that the many negative general advisement posts and threads that target so many makers of routine quality lights have not been confirmed by my happy experience.
I like reviews that are not 99 and 44 hundredths percent syrupy sweet. Tell it like it is with the sample that the reviewer has is ok/fine with me.