Help needed to identify emitter

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Smarczak260
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Help needed to identify emitter

Hi Guys

Does anyone know what this emitter is or could suggest replacement?

It is from snap on neck flashlight. Runs on 3.5v and has around 125lm as per snap on website. It just stopped working and I need to find replacement or use different emitter in its place.

Correllux
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Welcome to BLF!

Guessing it’s a knockoff “Cree” of some kind. Can you desolder the emitter to get a look at the pad layout? I can’t tell if that lettering on the board says “3535C1” or not, but my first guess is that it’s a typical 3535 die size (3.5mm x 3.5mm for the square), in which case it’s probably compatible with all of the Cree XPL/XPE/SST20 types. Need to determine that first and then the world is your oyster and you can likely get a more efficient emitter that may bump light output a little, and you can choose your color temp and if you want a high-CRI version.

Are you positive the emitter is actually dead? The way those wire leads are bare, it looks like they could easily short out, so maybe so. You can easily test for this by applying 2-3 volts to the lead contacts (using a multimeter with a good diode test function or a battery/two batteries and some wires). Is there a electronic driver board anywhere, or is it just using that resistor by itself to control current? At any rate, probably a good idea to replace those wires or at least put some heat shrink on them so they can’t short on each other.

If you already have soldering skills and don’t need to buy stuff other than the emitter, you can probably fix this in fifteen minutes for just a few pounds if you can find an emitter locally. Ordering from China it’ll just cost a little more and you’ll have to wait awhile for it to arrive. Surely other good mail order options closer to home (Led4Power being a good one in Croatia). If you haven’t soldered before or reflowed an emitter then you can definitely still do this, but you’ll have to learn and spend a little on materials/tools. Some computer/phone repair shops will do this for you, too.

Here are a couple of stickied threads in the DIY section that you might want to look at:

Identifying emitters by photos (can mouse over the frames for different views and size comparisons): https://budgetlightforum.com/node/26665
Simple emitter reflowing method: https://budgetlightforum.com/node/46443

Smarczak260
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Thanks for your reply.

It does say 355C1 on the pcb.

Emitter is dead now, before I took the flashlight apart it was very very dimm compared to the other one. My guess is that it’s probably Xp-g2.
I can’t take the emitter off but friend of mine can.

I think I just buy 2 x xp-g2 and get him to change both emitters so in case this is not xp-g2 they will look the same after both get replaced.

Correllux
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Ok. You might have a hard time finding XPG2 at this point since is was replaced by the XPG3 a few years ago, but either would work as long as they are using the same contact pad design. Best to remove one for a look before you order. Since it’s dead, you don’t have to worry about abusing it with too much heat, so a lighter or candle could be used to remove it (try not to overheat it terribly to the point of lifting off or burning the masking material on the top of the board…likewise, try not to scratch through that coating on top).

Also, in addition to not wanting those bare wires to touch each other, you also don’t want bare wire to be able to contact the metal of the board in those cutouts and causing a short that way.

Smarczak260
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Thanks for your advice Correllux.

I’ll give it a go next week and report back.

Correllux
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