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General Category >> Technical >> LED Light Repairs
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Message started by Denman on Nov 24^th, 2011, 11:15am

Title: LED Light Repairs
Post by Denman on Nov 24^th, 2011, 11:15am

Recently bought some really bright LED lights.
Powered by (4) 18650 Lithiums, with hi/low voltage protection and velcro sack
1000 Lumen Cree XML LED.
Nice housing with O-Ring mount.
Battery charger.
$60 delivered.

Did the Denton 37 mile chip seal ride. One light failed.

After opening it up I found a component came loose. No big deal to fix if you're handy with a soldering iron.

LED's have a tiny power control board about the size of a quarter. All but one of the components are tiny so they hang on pretty well. That one component, an inductor is a ring about the size that would fit on a child's finger. Its relatively heavy and soldered to the board by two wires. On Chipseal it vibrates like a tuning fork.

Remove the O-ring/bar mount
Unscrew the glass bezel
Remove the reflector cone
With a tiny drill bit in one of the two spanner holes, unscrew the bezel around the LED
Carefully pull the LED/Board assembly out whlie feeding the case wire in near the mount you removed
Carefully pry the brass ring out of the aluminum base - the board is soldered to this brass ring....

Now you'll see the inductor. If you've gotten this far you'll probably see one of the wires was yanked out.
Push the wire back through the hole on the board and solder it
Now on the brass ring you may have broken the solder bead to the board.....
Before soldering the board to the ring, clean the brass ring at the edge where you will re-solder the board....
Keeping the board about 1/8" off the ring lightly tin the outer edge of the brass ring, just a spot
The ring takes a lot of heat and tinning it with the board away a tad prevents things from falling off the board at that point.....
Let the ring cool, push the board back into the ring nest and solder
Now take a piece of closed cell foam or a harden bit of silicone seal about 1/4" cube and insert it between the inductor and the housing
Don't hot melt it; its just hot enough it might melt the ROHS solder.....
You can glue it with silicone seal, but don't ever expect to service it again....
Now reassemble the light.

It took me about 7 minutes to fix my light, and about 20 minutes to type this up. I hope you find it helpful.

Title: Re: LED Light Repairs
Post by dd5339 on Nov 24^th, 2011, 6:18pm

Thanks for the tip!

I'm just curious on the brand and maker of the light if you would care to share.

Vicky and I have put together some flashlights running the Cree XM-L with a single 18650 that are working pretty well so far.

Semper Fi

Title: Re: LED Light Repairs
Post by Denman on Nov 24^th, 2011, 8:15pm

Sure, the site is http://tinyurl.com/7afk7qb

I'm guessing the vendor is something like "The Great Big Bike Light Company". [smiley=grin.gif] China manufacturers don't waste a lot of money on marketing. The LED is a genuine CREE from Durham NC.

If they put it in a nice $25 box, it could sell at the LBS for $350.

I saw yours the other night; when we passed mine was the leading trike and action lad had a xenon on his.

Title: Re: LED Light Repairs
Post by Opus the Poet on Nov 24^th, 2011, 11:24pm

It appears to be a knock-off of a MagicShine light. The same LED and batteries and a visually identical optics.

Title: Re: LED Light Repairs
Post by bobcat377 on Nov 25^th, 2011, 6:41am

Very nice repair. About all I can do is patch tubes.