Genius required. Cree light fault.

[I like Skol]

I bought THIS FRONT LIGHT for my son's bike last autumn. I know it's cheap and cheerful but it is actually really bright and at a price I won't be too upset when he loses it or it gets pinched off his bike in the school bike park.

A few weeks ago he arrived home in the pouring rain and I noticed his front light wasn't on. He said it stopped working part of the way home. I changed the batteries but this didn't help and noticed a bit of moisture inside the casing so stripped it down and left it somewhere warm to dry for a few days.

Now it still doesn't work but if I switch the switch on and screw the cap on the LED flickers and sometimes comes on full power (I still have spots in front of my eyes just thinking about it!). I can get the torch fully assembled and it is still working but the moment I switch it off it will not come back on. I have resoldered any connections I can get to and tested the continuity of the switch and all the casing contacts with a multimeter and everything tests good but the torch still won't work.

I suspect there is some clever circuitry built into the LED mount that acts as a starter for the Cree and this is damaged and that by screwing the casing together this is causing some sparking/pulsing in the current that is imitating the starter?

Aside from the obvious "throw the cheap tat in the bin" is there any hope for this torch which apart from not working appears to have the potential to be perfectly ok?

 

[numbnuts]

At that price I would not worry bin it, we live in a throw away society

 

[wiggydiggy]

I had a similar one fail in the same way, seller just sent a replacement no Q's asked so I presume cheap as chips.

+1 for trying to fix but keep the battery pack/mount and bin the rest. Buy a new one but I'd recommend some silicone sealent on it - no issues with mine since I did that.

 

[Trevrev]

I had the same problem with a Halfords light. Moisture was finding it's way in, I just sprayed the circuit board and all the workings with WD40 and it's worked ever since.

 

[I like Skol]

I had the same problem with a Halfords light. Moisture was finding it's way in, I just sprayed the circuit board and all the workings with WD40 and it's worked ever since.

OMG! did you just say W*40 on a cycle forum?

I think it is dry, it has been sat above the oven for about 2 weeks but I may give it a little squirt and see what happens.

 

[Wobblers]

I'd check to see if there's anything obviously wrong, such as cracks in the circuit board or electrolytic capacitors that have bulged (you can spot those if the top of the capacitor is bulged outwards into a dome shape - it should be flat). Also check to see that there's nothing shorting the circuit board and that it doesn't touch any exposed metal parts of the case. Other than that - it might be the switch? If water gets into the switch, it could easily corrode the contacts which would cause the symptoms you're seeing.

 

[Andy_R]

OMG! did you just say W*40 on a cycle forum?

I think it is dry, it has been sat above the oven for about 2 weeks but I may give it a little squirt and see what happens.

Using WD40 in the manner it was designed to be used is perfectly acceptable. Using it to lube chains is not.