Bought a original L6 and decided to upgrade it to a whiter brighter XHP70.3 and a smooth reflector. I ordered the reflector and emitter from the Convoy store on AliE. I soldered the new emitter in, which was more difficult than I anticipated. I had to redo it once but I have the same problem. Once I reassemble the light and screw in the lens the light won’t turn on unless I unscrew the lens a little. I used a new gasket.
I also got a fingerprint on the smooth lens and tried to wipe it off with a tissue and it seems to have ruined the perfect reflective surface. Tried dish soap, hot water, and different cloths, but the surface seems a lot less shiny and reflective now. Alcohol? Are the lens serfaces that fragile?
It sounds like that when the bezel is screwed in tight, the reflector puts pressure on the MCPCB (via the gasket) and that causes something to not have a connection anymore. I assume you bought XHP70.3 as already (re)flowed on a copper MCPCB? (So it’s likely that it is reflowed alright.)
I suspect that it might be one of the solder connections of the wires that disconnect when you screw the bezel in tight. Might be difficult to visually see, but it could just be enough as to cause a loss of contact.
Could you make a photo of the LED/MCPCB inside the flashlight, so I/we can see how the soldered connections look like?
Paper (even a tissue) is (way) more abbrasive than a lot of people think it is, so in general it is wise to not use it on sensitive/soft surfaces, like carpaint, plastic screens of (cheap) phones/tablets, (sun)glasses with non-glass lenses or acrylic panels/windows, etc. Real glas could/should be fine, although possible coatings on them might not be.
But do you mean the lens (so the glass) with AR coating or do you mean the surface of the smooth reflector? Certainly the reflector coatings (certainly smooth) are VERY sensitive and scratch really easily, even with a soft(er) cloath.
If it’s the glass lens, it’s possible that the AR coating is damaged. There is not much you can do about it, other than trying to polish all the coating of and see if the glas underneath is fine. (Or buy a new lens.)
If it’s the reflector coating that is damaged, there is also not much you can do; in theory you could decide to “scuff up” the whole reflective coating, to make more uniform again, but the reflector will (likely) not perform as a new one. (Buying a new one is the other option.)
All in all it’s good practice to be carefull with wiping down (possible) soft/sensitive surface and to not use paper for it, but rather a microfiber cloath and even a soft cotten cloath/rag (like an old t-shirt) is already safer (in my experience) than paper.
I clean reflector with special soft paper which is used for cleaning camera objectives.
For cleaning glass I use brake cleaner made by Forsch which is alchocol based and evaporate without any residues but I can’t find it in last few months because it is out production.
I have two spray bottles of it and I use it sparingly now, only for flashlights and for repairing watch movements.
