HELP Led fell off board (tank007 tk-506)

[swtxtitan]

Ok guys heres the delima. Im just getting to high quaility lights and this happened.

The small board with the LED still attatched, fell off the main board. How should i glue it back? or solder it on?
Also, i used someone elses pic, hope they dont mind.

 

[SirJMD]

I would contact the shop where you bought the light !

If there's no warranty, then you can solder it back on.

 

[swtxtitan]

The LED is still attatched to the small board, it just fell off the big board. I'm wondering how to reattach it. If i lay it on the board it lights up, but any slight movement, it turns off. I just dont know where to glue or solder, or what exactly to use.

 

[swtxtitan]

maybe i could cold solder it on??

 

[sigsour]

If the terminations are underneath the small board then you should really use solder paste and heat each side with a heat gun.

 

[Lighthouse one]

You will find it very difficult to solder the LED back on properly. I would buy an Led that is on a board the same size , and reglue the board...or screw it down if possible. Much easier to solder the 2 wires.

 

[swtxtitan]

Well, does anyone know how the board was originally attched to the big board? It seems like soldering would be difficult, kinda like trying to solder two flat metal sheets together.

 

[Lighthouse one]

At the factory they are machine soldered. Some CPF'ers can duplicate it, but it is much better to just get another led on a star. DX has some for example.
Bare Led's can be epoxied to a heat sink, but heat transfer is critical-so these things must be done right or the Led will overheat quickly. If you really want to fix it...go with an Led that is already mounted.

 

[Linger]

Lighthouse,
Thermal transfer is good but more important is the electrical contact - without that its not going to get hot at all

swtxtitan,

I laughed reading that, this isn't anything quality at all.

Say it with me, 'the emitter fell off the 10mm circular engine'
Your 'small board' is the ceramic substrate the emitter is built on, so no those don't come off.
When the unit was made the emitter was supposed to be reflowed onto that circular light engine and sounds like the job was botched. It needs to be soldered back on for a few reasons, mainly electrical contact, but also thermal transfer from the center slug to the engine (and thus to the light body).

To fix this, the electrical leads need to come off.
the engine needs to be removed from the pill (the light body)
clean the back of the board (need to remove some thermal paste if you're lucky)
-a little sanding of contact pads to remove old solder
-clean contact pads w isopropal alcohol (both board and emitter)
-apply some solder paste (very little, see reflow soldering)
-reflow emitter back onto the board (takes ~30seconds start to finish)

Reassemble:
thermal paste on back of board to light pill (light body)
reconnect electrical leads

This is not the simplest diy to fix, but may be the 3rd or 4th simplest task? But if you're new it's right impossible.

 

[Bimmerboy]

Unless used as a practice piece to help build some modding skills, I'd chalk this light up as a goner. It's most certainly not a quality light, and trying to fix it will cost at least as much, and probably more than the light itself.

Save the blood, sweat, and tears for other projects, and the money for a much better light!

 

[hyperloop]

if you got it from DX or KD i am afraid to say that it doesnt really qualify as a high quality light, those sites are known for budget lights. i have had a few lights from them fail for no discernible reason, one was supposed to be a 3 mode light but was locked on high, no amount of reverse clicking made it change modes. Then i dropped it, and now it's locked on low.

 

[swtxtitan]

Thanks fellow CPFer's. My statement about "High quality" was a little misleading. I was actually refering to my eagletacs, streamlight, and fenix lights. These are the lights that really sparked my intrest in the world of flashlights. I've actually fixed the light for now, lets see if it lasts.

 

[Bimmerboy]

My statement about "High quality" was a little misleading. I was actually refering to my eagletacs, streamlight, and fenix lights.

Cool. Seeing you've been here a year, I was kinda' worried about ya'... lol. :sweat:

What did fixing the light entail?

 

[swtxtitan]

I actually used an expoxy glue to set the emitter back onto the engine. I think that the contacts are on the opposite ends of the ceramic substrate, so I avoided glue on these ends (just the middle). Then i perfectly centered the LED and put a small dab on the outside of the substrate. Its holding fine for now, and the light is working perfectly. If it doesnt last, thats ok, i will just purchase a new engine.

 

[hyperloop]

Cool. Seeing you've been here a year, I was kinda' worried about ya'... lol. :sweat:

What did fixing the light entail?

+1

 

[Linger]

Nice sounding hack, well done. Pics?

Don't take this one to mars with you or anything, but great job working out a solution. And your competence and experience is bumped up a few more notches.

 

[choaticwhisper]

Yeah thats exactly not "High Quality."
But either that was poorly soldered in the first place or maybe the light was on enough to heat up a poor heat sink, Making the solder melt, releasing the led off the board.