Originally Posted by
2manybikes
As they say in the instructions, you need to keep the contact surfaces clean. This includes the threads, they use them to pass current for the light to work. Also the ends of the barrel where it touchs the head and the end cap. Dirt or grease on the threads or flats can cause a problem. Even invisible corrosion from being outside can do this. Just a couple of ohms can be a problem with low voltage stuff like this.
You also need to carefull clean the contacts with a Q-tip and a little alcohol. (All this is in the instructions).
I have saved watches, calculators and other small things just by wiping the contacts with a flannel shirt and they kept going for a long time. It also works great on small bike lights, like blinkies.
The corrosion can be almost invisible, or if you look close you can see it, just a little discoloration. Even thought the lights are water tight they can get condensation inside them in the winter from going inside and out. This can corrode the contacts. The symptoms you describe fit this perfectly, it happens with all kinds of things, it's very common. If you use it in the cold (as you do) you need to stay on top of this.
This is an on going thing, not a one time problem, you need to clean the contacts, threads and lands periodically, especially in the winter. Your symptoms sound perfectly normal and typical to me. Nothing unusual. I can't believe this has not already come up, did I miss it?
I just tried your advice. I cleaned the contacts at both ends, threads, battery ends w/ ETOH and Q tips. I even used a microscope to see how dirty/clean the contact points were. The threads were dirty, contacts not bad. Cleaned them all anyway. I turned off the room light and fired up the Fenix. I compared it to my bike halogens. Halogens won. When the Fenix was new the halogens lost. The batteries have 30 min run time on them so will test with fresh batteries tonight. I also tried the low levels on the Fenix and saw no light until I looked directly at the lens. There was one low level but it was so low that it did not show up on the wall in a dark room.
When I removed the lens end to clean I looked at the contact at the base of the lens. It looked OK but around it was a green background with 4 or 5 solder looking areas. 2 or3 had what looked to be solder(silver) in them and 2 areas (brass) were not filled in with this silver stuff. This may mean nothing, just an observation.
Thanks for the advice. I really was hoping it would solve the problem. I was hoping to make it to the end of winter w/out sending it back. I could ride 'as is' with less power but will opt to return. I really like the strobe at twilight. The way it lights up the signs is so cool. It still lights 'em up but not as brilliantly as before. Charlie