AceBeam X80 - Problem with UV LED

Flying_Luminosity · 2018-08-31T03:40:08.000Z

For the past half year, I’ve been very happy with the X80. At least until today, when I noticed something had happened to the UV LED (Nichia 276A). Instead of a bright purple, it now emits an almost white light, with only a slight purple tint. UV-reactive substances still light up, but the output is a lot weaker than before. Previously, it hurt my eyes just to look at the light sideways when I held it at arm’s length. But now I can easily look directly into it. i have also tested it outside, and I need to stand a lot closer to a building to make all the net curtains in the windows light up.

What has happened? And what can I do?

Henk4U2 · 2018-08-31T08:00:41.000Z

Before I (try to) go deeper into the matter at hand: NEVER look into a light with a 365nm UV-emitter. Not directly, nor from the corner of your eyes. Also avoid looking into the light reflected by windows, mirrors, or kitchen and bathroom tiles.

Member djozz has written a lot about UV emitters, and done a lot of testing and measuring. In this thread he has tested the Nichia you are referring to. Seems that Nichia’s have a higher efficiency but also a different heat-transfer than most led’s. They seem to be more vulnerable to improper assembling (post #19). It’s quite possible that your Nichia is (partially) fried because of that. I hope you can get warranty from your seller.

Not to be rude: there are still 16 hours left to win a Convoy S2+ with 365nm UV led in my 2000 post GAW .
The Semileds 365nm UV emitter in that light is perhaps not so efficient as the Nichia, but more robust. And is flowed onto a Noctigon board.

Flying_Luminosity · 2018-08-31T16:15:08.000Z

Henk4U2:

Before I (try to) go deeper into the matter at hand: NEVER look into a light with a 365nm UV-emitter. Not directly, nor from the corner of your eyes. Also avoid looking into the light reflected by windows, mirrors, or kitchen and bathroom tiles.

Member djozz has written a lot about UV emitters, and done a lot of testing and measuring. In this thread he has tested the Nichia you are referring to. Seems that Nichia’s have a higher efficiency but also a different heat-transfer than most led’s. They seem to be more vulnerable to improper assembling (post #19). It’s quite possible that your Nichia is (partially) fried because of that. I hope you can get warranty from your seller.

Not to be rude: there are still 16 hours left to win a Convoy S2+ with 365nm UV led in my 2000 post GAW .
The Semileds 365nm UV emitter in that light is perhaps not so efficient as the Nichia, but more robust. And is flowed onto a Noctigon board.

Thanks for the safety tip. So it’s most likely a problem with the LED itself, and not with the driver not being able to supply enough current? I’ll get in touch with BangGood, but I’m a bit worried about high postage costs for return shipping, unless there is an option to get it repaired locally. Also, I’m not sure either whether the light still has a seller guarantee after just over six months, or whether I need to make use of the 5-year warranty that AceBeam provides.

djozz · 2018-08-31T16:27:12.000Z

As Henk pointed out, the 276A is a rather sensitive led that does not like getting hot and being overdriven. I’m not sure if Acebeam was aware of that but here on BLF it has been found years ago. What happened to one of my lights in which a 276A was slightly overdriven is that the white stuff in between the traces on the led disappeared and that the led started emitting lots of visible light, with output loss of UV.

Healthy led on the left, damaged led on the right.

Flying_Luminosity · 2018-08-31T17:01:09.000Z

I guess that means I’ll have to think about whether to send the light back for repair, or whether to ask someone to reokace the LED with a Semileds one.

At least I’ve got to commend AceBeam for not gluing the bezel on - just manged to easily unscrew it, so will try to take some photos later on when I’ve got more time.

djozz · 2018-08-31T17:29:51.000Z

Flying Luminosity:

….or whether to ask someone to replace the LED with a Semileds one.

That will not be the best solution. The reason to still choose for Nichia leds despite that there are leds out there with better output, toughness and better footprint (the Semileds one is not the best anymore btw, I would go for a LiteOn, LG or Seoul Viosys led), is because Nichia 365nm leds emit very little visible stray light compared to other 365nm leds out there. The other leds need the visible light filtered out by a UV-pass filter to function well (if the purpose is detecting fluoresence by UV radiation) while the Nichia’s perform well enough without filter (well, if they are being pampered well ). Clearly in the way that Acebeam has designed the head of the X80, they did not provide for adding a UV-pass filter over the middle section.

Flying_Luminosity · 2018-08-31T21:51:45.000Z

djozz:

The reason to still choose for Nichia leds despite that there are leds out there with better output, toughness and better footprint (the Semileds one is not the best anymore btw, I would go for a LiteOn, LG or Seoul Viosys led), is because Nichia 365nm leds emit very little visible stray light compared to other 365nm leds out there.

That’s what I really liked about it, although admittedly I’ve only had two other UV lights to compare it with (a cheap one and a Nitecore), and both were disappointing in comparison.

Unfortunately I didn’t manage to get a good close-up picture, but it does seem that there is none of the ‘white stuff’.

I guess I’ll need to get in touch with BangGood, and see if I can get a replacement.

mortuus · 2018-09-01T11:37:27.000Z

wow that sucks, i hope banggood will take care of that, not exactly a cheap light

Flying_Luminosity · 2018-09-01T18:40:39.000Z

mortuus:

wow that sucks, i hope banggood will take care of that, not exactly a cheap light

I’ve contacted AceBeam, to see if there is anywhere in the UK where I can send it for repair. Really not too keen on the idea of having to send it back to China, and waiting several months to get it back. Otherwise I’ll just have to grin and bear it.

mortuus · 2018-09-01T18:47:23.000Z

please keep us posted about this, if there is anything that bugs me is when u have an expensive light and u get no help with warranty… it should clearly cover this lets hope u get help.

Flying_Luminosity · 2018-09-02T03:23:33.000Z

mortuus:

please keep us posted about this, if there is anything that bugs me is when u have an expensive light and u get no help with warranty… it should clearly cover this lets hope u get help.

I know that there are several manufacturers who are known to provide outstanding service, so let’s hope that AceBeam is one of them. It would be nice if the quality of their customer service matches the price range of their products (and usual quality, from what I’ve read - it seems that I’ve just been unlucky).

Flying_Luminosity · 2018-09-03T11:15:50.000Z

AceBeam got straight back to me this morning, and said I could send them the head for replacement. I’ve asked for the address - the person replying to my email said it would cost me around $20 in postage costs and that delivery would take about two weeks, so I assume he means their China office. But I far prefer that to all the hassle of going through BangGood (weeks of sending emails backwards & forwards, recording videos of the problem, and so on), so I can’t complain - especially as the warranty says the flashlight should be sent back to where it was bought if there are any issues, and to only contact AceBeam if there is a problem with the seller.

Flying_Luminosity · 2018-11-26T18:52:13.000Z

Just a quick update, after receiving my light back.

It took 17 days for delivery to China, and another 17 days before I was asked for my phone number, which is apparently required by DHL. Return delivery time was only eleven days but it took me another four weeks to receive it, since I was not around due to illness, and not available via phone during this time.

AceBeam were very professional, and I am happy that they agreed for me to send the head to them, instead of having to go through BangGood. Despite the problem with the UV LED, I can say that the quality of the light is outstanding. Unlike other high-powered lights that I have (e.g. Astrolux MF-01), I have little doubt that it would survive being dropped. In my opinion, the quality of their service matches that of their lights, and in future they will definitely be one of my first choices if I want to buy a new light.

10/10

klrman · 2018-11-26T20:52:24.000Z

Thanks for the update. Have two X80's now and good to know they stand behind their warranty.