# How to change LED?



## 13r0wn7 (23 Jun 2014)

I was wondering if anyone knows how you can change these? 
I have took the cover off and this is what it looks like.
I Believe the led is cree xlamp xm-l series.

Under this unit is a solid metal plate which cannot be removed. 
Apparently these lights are designed to easily change the led..

I was thinking does it just pull out and you just put another back in? 

Any info would be great, 







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## ale36 (23 Jun 2014)

HI they are surface mount soldered you should be able to remove them with a soldering iron and then solder the replacement back on


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## 13r0wn7 (23 Jun 2014)

How would I remove the current led? Where would I put my solder?


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## ian_m (23 Jun 2014)

http://en.wikipedia.org/wiki/Desoldering

With surface mount normally you would use a hot air gun and suitable shield to protect other parts.

However using a soldering iron and solder wick, you can hopefully "suck away" enough solder to free the LED.

Solder wick here.
http://uk.rs-online.com/web/p/desoldering-wicks-braids/3143289/

Then put replacement LED and re-solder in place.

Are your 100% sure the LED has gone and not the driver ?

I have never seen a Cree part ever "just fail", always the driver blowing up or even worse the driver destroying the LED and thus when you replace it, it then fails again. The words "Chinese" & "Ebay" & "LED driver" is the cause.


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## 13r0wn7 (23 Jun 2014)

No there all working fine. I just want to change some 10k for some 6k's  

I have watched a youtube video and all he did was heat the led with heat gun and then put the new one on with abit of flux aswel. 

May give it a try if I feel confident enough! 


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## ian_m (23 Jun 2014)

Then solderwick and soldering iron is easiest and cheapest way.


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## Jamie McGrath (24 Jun 2014)

You will need a solder sucker as well.


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## ian_m (24 Jun 2014)

Jamie McGrath said:


> You will need a solder sucker as well.


Nope, you will damage the LED &/or PCB with a solder sucker, which is why you use solder wick. I have removed some quite monstrous PLCC packages eg 208 pin parts, just using solder wick. Just keep wicking till all solder gone and hopefully you will get the part off.

Might need to add more solder (I know it sounds daft) so the wick can work fully.


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## 13r0wn7 (24 Jun 2014)

There is no solder visible at all. I have watched a video and all that was used was a heat gun? 


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## ian_m (24 Jun 2014)

13r0wn7 said:


> There is no solder visible at all. I have watched a video and all that was used was a heat gun?


 I can see solder in your picture. Heat gun is "better" but have you got a heat gun & need to protect other bits and pieces on the board from being heated. Solder wick was just a cheaper option.


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## 13r0wn7 (24 Jun 2014)

Ah ok. I am just going to buy a cheap gun on eBay there not to bad price really! 


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## 13r0wn7 (24 Jun 2014)

What would you say would be a good and easy to make/get heat shield to protect everything else?


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## ian_m (24 Jun 2014)

The heat shields we have at work are steel, designed to cover the particular chip in question. In your case you could probably fashion something using an old tin can. You just need to stop the hot air "escaping" onto something it shouldn't and damaging it. Favourite beginners mistake is going hell for leather and accidently desoldering half the components on the board.


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## 13r0wn7 (24 Jun 2014)

I was thinking of getting some aluminum 2mm thick and cutting the hole for the chip..?


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## ian_m (24 Jun 2014)

13r0wn7 said:


> I was thinking of getting some aluminum 2mm thick and cutting the hole for the chip..?


Try it, sounds OK.


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## 13r0wn7 (24 Jun 2014)

I have just spoke to a family member about it and he says i will be crazy to try this! He said there's no way your going to be able to do it without damaging anything. 

How much risk would you say there is?
Even with aluminium sheet cut to go around led.. :s

Also it would be a normal heat gun not a specialised solder one


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## ian_m (24 Jun 2014)

Ah. You need a specialised temperature controlled gun with fine nozzle. A paint stripper gun is not the same.

This is a proper desoldering gun, with suitable nozzle and shields.
http://uk.rs-online.com/web/p/heat-guns/3153387/
and nozzle
http://uk.rs-online.com/web/p/heat-gun-accessories/3253279/?origin=PSF_438851|cav

As I said if you haven't got a proper gun try solder wick.

A paint stripper gun is far far too hot, not temperature controlled and far to big nozzle. It will cause damage left right and centre.


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## 13r0wn7 (24 Jun 2014)

Ohh! Better not then!!!
I have been looking at this wick method seems ok but what if it doesn't take enough solder off? Also I think its a solder paste? 
Also seen this on eBay http://www.ebay.co.uk/itm/AT858D-Ho...Home_Garden_PowerTools_SM&hash=item54095db5d7


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## ian_m (24 Jun 2014)

Bit more expensive that solder wick. But is the correct kit with temperature control and nozzle and would probably be fine.

You might have a Maplin nearby.
http://www.maplin.co.uk/p/de-soldering-braid-15mm-width-n48fx

Solder paste is the stuff they print on, when it melts it becomes solder, same stuff as in the coil of solder you buy (except paste is many many times more expensive).

You could just try the apply lots of heat from soldering iron method of removal.
- Apply lots of solder to joint to give some "volume" for soldering iron tip to "stick" into.
- Apply soldering iron.
- Push with screwdriver/tweezers until part comes away.
- Clean PCB with solder wick to remove excess solder left from stage 1.

I have removed some quite monster chips this was, when proper equipment was not available.

You could also Dremel away the LED, leaving just the pads/leads and they will easily desolder.


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## 13r0wn7 (24 Jun 2014)

Thanks for your help Ian. Undecided which way to go yet. Just one last thing the temp control what would you have it set at? 


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## ian_m (24 Jun 2014)

No idea, solder melts at 220C (lead free stuff) so needs to be say 300C. Main thing is not temp but air flow so you don't destroy something you shouldn't.

At work I use the guns on hottest (6 out of 6, setting or 5 if being careful) but low air flow so as to not damage other things.


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## 13r0wn7 (24 Jun 2014)

Wish you lived near me! 


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## ian_m (25 Jun 2014)

Looking at the data for Cree XM-L LED's you should be able to remove the LED using just a soldering iron (been there done that, got T-shirt etc).

Apply more solder to edge of LED, doesn't matter about shorting contacts (leaded solder will flow better, if you can get it). Apply soldering iron and hold until solder under LED melts and lift LED off using tweezers or fingers if "hard".

To replace LED, solderwick the pads clean, place LED on, ensure right way round, apply solder, probably all sides need solder applying to ensure good coverage. Use solder wick to remove excess solder. Check not shorted using a meter and job done.


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## 13r0wn7 (25 Jun 2014)

Sounds a cheaper way then paying for a heat gun which seems abit risky. 

Everything I have looked for surface mounted they heat the star on hot plates which is impossible in my case! 

Thanks Ian 


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