B&M Lumotec IQ2 Luxos U Senso fault?

[JulesP]

My Lumotec IQ2 Luxos U Senso has started switching itself on while riding, and does so repeatedly, despite me switching it off using the handlebar button. In short, I can't turn off the light for more than a few minutes. This is recent behaviour, which suggests a fault either in the light or the switch. Has anyone had the same problem and figured out a solution..?

[vorsprung]

Sounds like dirt on the sensor

I tried googling for where the sensor was exactly but the only steer was "probably on the underside"

[Kim]

My bet's on behind the translucent rubbery bit, with the blinkenlights.  I think that's what they've done on the IQ-X, and the Cyo's sensor (which is somewhat easier to spot) is rear-facing on the underside of the switch ring.

[grams]

The sensor is behind the translucent power switch IIRC. Although my recollection is that it’s only used to switch between day and night modes rather than on or off.

My only advice is to check your warranty status.

[JulesP]

I think the light sensor is only used to adjust brightness automatically when the light is on – the light shouldn't be switching on by itself when off (or at least it never used to). A trip to the LBS is on the cards, I guess.

[Kim]

On that basis, I reckon something's got wet...

[Pickled Onion]

What is the guarantee length on these? I have just had to replace one that stopped working.

[jsabine]

What is the guarantee length on these? I have just had to replace one that stopped working.

Think it may depend where you bought it. Rose offer 5 years IIRC, but I'm not sure that other retailers do.

[JulesP]

I think a lifespan longer than 18 months is a reasonable expectation, though I hope not to be dragged into that conversation...

[Pickled Onion]

What is the guarantee length on these? I have just had to replace one that stopped working.

Think it may depend where you bought it. Rose offer 5 years IIRC, but I'm not sure that other retailers do.

Aha, thanks, yes I've found it now. And the receipt - Jan 2015 

[igauk]

FWIW Rose refunded mine without a quibble earlier this year, was about four years old. In a change from the usual Luxos U behaviour mine failed in the dry mid ride. Fortunately in daylight, I only noticed as it stopped charging my GPS and eventually the day running lights ran out of juice. Broken connection inside somewhere me thinks. Got an IQ-X now but not used it in anger yet.

[fd3]

Mine flickers on/off the high beam.  Second hand so warranty, but it mostly works.  My X lasted less than a month, whereas my old spec cyo is going strong for over 5 years.  I’m considering asking rose whether they will swap my X for a cyo.