Busch & Müller - Luxos U Lumotec IQ2

[energyman]

If any one has experience of this front light, mine has now started to stay on all the time.
It means I can't use the USB output to charge the Sat Nav or run my portable kettle {  }
Batteries are OK, checked all the obvious things etc.  B&M Help line not much help as it is 2+ years old..
No water ingress.

[Danneaux]

...mine has now started to stay on all the time.
It means I can't use the USB output to charge...

Most likely a switching issue, but don't neglect the possibility a bit of dirt or mud has blocked the light sensor. They are sometimes a bit hidden, usually on the underside. It is a slim chance, but worth checking.
Otherwise, it may be the switch itself.

I depend so much on the reliability of my charging and light functions, I prefer separate devices. It goes against the grain of my trying to go with a more streamlined approach, but in this case, it has proven to work well for me.

I sure hope you can get the light sorted. Please let us know how you come out, e-man.

All the best,

Dan.

[mickeg]

I ordered a Luxos U for my new build but it has not arrived yet.

When I have electronics that are acting up with finicky electrical contacts, I usually try to get some tuner cleaner into the contacts, then operate the switch a few dozen times before any tuner cleaner evaporates.   I have an old cassette player and AM/FM/shortwave radio that needs some tuner cleaner every other year in the switch.

Since I have never had a chance to look at a Luxos U, I do not know if there is any chance of getting any tuner cleaner past waterproofing of the switch.  But that has never stopped me from trying.

I did a quick google search for tuner cleaner and it looks like it now is usually called contact cleaner instead of tuner cleaner.  Maybe nobody has any old vacuum tube operated tuners any more?

[energyman]

Typical.... as soon as I posted I did a ride down the fen to the bacon buttie shop and it worked perfectly, probably feeling unwanted as had been riding my e-bike for a change.
Thanks for comments.

[mickeg]

Now that I have received my new Luxos U, I can't see anyplace that I could get any tuner cleaner into it.  So, it is a good thing yours came back to life.

Since there is a switch on the headlamp unit and also the remote switch, if it stops switching, would using the other switch be the solution?  Or did that not work either?  If both switches are dysfunctional, that would suggest that the electronics went bad, or in your case temporarily bad.

I see there are two screws in the top of mine.  If mine stopped functioning, I would be tempted to look inside.  But not until after my warranty has expired.

My heart rate monitor died on me while in Iceland and the rain there, see photo.  But after it dried out, it started functioning again, for a while.  I suspect that some of these things can get finicky in wet weather.

[energyman]

Removing the two top screws and gently releasing the top uncovers a couple of Lithium (?) batteries and a small circuit board. 
I tried pressing the back of the light switch and it had the same effect as the handlebar one.
I can't charge anything whilst the lights are on.
Just glad it started working the way it is designed.
Whatever "they" say some electronics just doesn't like damp.

[mickeg]

Removing the two top screws and gently releasing the top uncovers a couple of Lithium (?) batteries and a small circuit board. 
I tried pressing the back of the light switch and it had the same effect as the handlebar one.
I can't charge anything whilst the lights are on.
Just glad it started working the way it is designed.
Whatever "they" say some electronics just doesn't like damp.

Slightly off topic:  I always get nervous about buying something that has a proprietary Li Ion battery installed that can't be replaced.  That made me a bit slow in buying a Luxos U, but I eventually bought one a few weeks ago.  A few days ago while I was doing some google searches to try to learn more about the LED lights on it and what they meant, I found this link to a forum posting by someone that replaced some batteries:
http://www.bikeforums.net/18938859-post19.html
Which I promptly saved to my hard drive so that in a few years I might be able to figure out how to replace the battery assuming it will fail in a few years, most likely soon after the warranty is up.

So far I am quite happy with my new Luxos U.  I went for a short ride last night to try it out in the dark.  Very nice light pattern.

[onebikeoneworld]

I liked my Luxos U, until it broke. And then I got a new one, and it failed again. The first time they replaced it under warranty, the second time it was out of it (because they counted from my original purchase, not the time of the replacement). I didn't really use it much for charging things, but I did like the light pattern. Now I just use a Black Diamond Spot headlight. Not as good, but vastly cheaper and less likely to break.

[mickeg]

What broke?

[onebikeoneworld]

A variety of things. Sometimes it'd get stuck on, so when you'd turn it off it'd turn itself back on again until the battery ran out. That was especially fun when it'd only do it for a very short time, and then flicker between on and off. It'd take hours for the batteries to die because it'd only come on for a short time, a torrential downpour on the way in to Chisinau was the trigger for one of those. The final problem with it was that the light would show on the button, and on the back of the light itself showing power going in, but there was no way to turn the light on. It also wouldn't USB charge then.

I've had the old and new design, and neither of them have worked out the water issue seems to be my take on it.

[mickeg]

A variety of things. Sometimes it'd get stuck on, so when you'd turn it off it'd turn itself back on again until the battery ran out. That was especially fun when it'd only do it for a very short time, and then flicker between on and off. It'd take hours for the batteries to die because it'd only come on for a short time, a torrential downpour on the way in to Chisinau was the trigger for one of those. The final problem with it was that the light would show on the button, and on the back of the light itself showing power going in, but there was no way to turn the light on. It also wouldn't USB charge then.

I've had the old and new design, and neither of them have worked out the water issue seems to be my take on it.

Thanks for the description of the problems.