Repairing LED circuit board

Ya’akov

Joined Jan 27, 2019
10,261
Did you note that it’s a SMD, or Surface Mount Device? They have no pins or leads to solder to. Generally, SMD devices require different soldering techniques. Some require special equipment.
This is spot on, but that being said, doing a one-off inductor is probably achievable given it is large and not so heat sensitive.
 

Ya’akov

Joined Jan 27, 2019
10,261
This https://www.ebay.com/itm/858D-Solde...ering-Hot-Air-Gun-Tool-3-Nozzles/192010037941 is cheap, decent quality, and has other uses besides reflowing solder (e.g.: shrink tubing, softening plastics, etc.)

That, some flux, and some solder (or solder paste might be easier, and you could probably do it.

You will need good solder wick, though, to clean up the board.

I do believe you could do it, if you are methodical and careful, and practice a little.
 

pmd34

Joined Feb 22, 2014
529
Don't let 'em all worry you! The pads on the PCB are plenty big enough to get the soldering iron onto and have the inductor in place at the same time. Clean off the old solder first with a solder sucker, or solder wick, put the inductor in place, add a little bit of flux, and its no problem with some solder wire and and iron!
 

Ya’akov

Joined Jan 27, 2019
10,261
Don't let 'em all worry you! The pads on the PCB are plenty big enough to get the soldering iron onto and have the inductor in place at the same time. Clean off the old solder first with a solder sucker, or solder wick, put the inductor in place, add a little bit of flux, and its no problem with some solder wire and and iron!
The problem with using an iron is overheating and lifting the pad. You or I could manage with the iron because we understand the problem but it is quite difficult to do if you aren't very familiar with soldering. Not impossible, just hard, and I don't know about you but I destroyed quite a few pads before I got to the point of knowing how to do this.

Hot air is a lot harder to mess up if you take time and care. The heating is less critical, it is harder to do damage.

He can certainly try to do it with an iron, the exposed leads headed to the bottom makes that possible, but if I am giving advice to a beginner it includes using the right tools, for the reason they are the right tools. In many cases, better tools are more benefit to the beginner than the expert who knows how to work around the shortcomings of the poor ones.
 

pmd34

Joined Feb 22, 2014
529
You or I could manage with the iron because we understand the problem but it is quite difficult to do if you aren't very familiar with soldering.
:rolleyes: You flatter me sir! Point taken though, getting overzealoused with a too hot iron can lead to delaminiation, but it should be ok with a bit of care... and that they are aware of the potential problem now!
 

Ya’akov

Joined Jan 27, 2019
10,261
:rolleyes: You flatter me sir! Point taken though, getting overzealoused with a too hot iron can lead to delaminiation, but it should be ok with a bit of care... and that they are aware of the potential problem now!
If he is going to attempt it with an iron, he needs to very carefully clean the pads of solder, re-tin them with a good Sn/Pb solder, very lightly, tin the component with the same solder, just a coating to it can be nearly flush, then reflow that on one side, then the other, then add more solder to each side.

He might be able to use a drop of cyanoacrylate to hold the choke in place and make it easier, which I have done for some recalcitrant components in the past. I wouldn't do that, though, unless holding the component by hand failed first, and in any case, only the tiniest amount.
 
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