EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: aroby on December 19, 2019, 05:39:34 pm
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I have a swimming pool with Savi Melody lights installed. They keep failing, and the supplier won't replace them anymore. So, this time I'm going to try to fix the light.
The electronics seem fine, although I will replace the caps - you can see heat discoloration on the housing next to where they are located. What has failed is the red LED chip. It will be tricky to replace, but the trickiest bit is determining the part!
I've not yet been able to test this on a bench, but I assume all the LEDs are the same as the green one (D5), with 16 LEDs. The chip measures 4.75mm x 3mm.
Thanks for taking a look. I hope I can save myself the $200 it costs to get a new unit.
Anthony
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First step is going to be to figure out what voltage and current the LEDs are run at. Once you've figured that out it should be a simple matter of searching Digikey or some other supplier for a suitable replacement. If in doubt about the current rating, you can always go with a higher rated LED to be on the safe side.
Are those bare solder pads connected to the same place as the LEDs that are directly wire-bonded to the PCB?
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The LEDs are looking like luxeon rebel.
https://www.digikey.de/de/product-highlight/p/philips-lumileds/luxeon-rebel-color-emitters (https://www.digikey.de/de/product-highlight/p/philips-lumileds/luxeon-rebel-color-emitters)
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Everlight has similar parts, same package
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From the PCB discoloration clearly they are failing due to getting too hot.
So you will want to lower the current going to them a bit.
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From the PCB discoloration clearly they are failing due to getting too hot.
I dunno, the pattern of the discoloration doesn't really seem consistent with heat (should be a more or less even discoloration around the LEDs). There's some strange discoloration around some of the vias that are nowhere near the LEDs. To me looks more like corrosion from moisture ingress which is a very likely scenario considering these are pool lights.
The LEDs might actually be fine and the PCB traces, via, or solder joint could simply have gone open.
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Certainly looks like heat to me, but not necessarily from the LEDs. What's on the back of the PCB? Perhaps the uneven heat is due to poor thermal contact?