SR-90 "donut" beam pattern issue

cujet

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Update: Olight repaired the light and it functions very well now. It took couple of months for them to repair it, however, it seems they did a fine job. It clearly has a new emitter. I'm very pleased with the focus, as it no longer has a donut beam pattern.

I have to say that I am quite pleased that Olight repaired my light. It was 4.5 years old and I half expected them to deny warranty. While I did not cause the failure, on something this old, you never know what to expect.







I have an original olight SR-90, about 3 or more years old. It sees regular use at the airport, hunting for critters, such as deer, possum and armadillo that dig holes on the grass runway or otherwise just get in the way. No estimate as to how many hours on the light, but I'm on my second battery, as the first one finally stopped being able to run the light for an hour.

The problem is this, the beam pattern is now a "Donut", and it's getting worse. It's still bright enough, and the beam's spot looks to be about the same size it's always been. But, it's clearly empty in the center now. And, that's a problem when looking for small critters, as the donut elongates when looking on the ground at a distance. It's also possible it's not as bright as when new. But, that's subjective, maybe if the focus was right, it would still be able to illuminate the trees on the other side of the runway.

I sent olight an email asking to purchase a new "head" for my light, but they failed to respond.

I've been reading the threads on SR-90 mods and figured someone here knows exactly what's happening with my light and how to fix it. I'm a capable "tech" and I have no problem taking it apart to repair or replace internal parts. However, it's always smart to ask first!

Thanks!!!
 
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cujet

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Just a quick observation. I looked at the LED emitter with a shade 9 welding helmet. The center of the LED looks darker than the edges. Possibly I have a bad emitter.

Any thoughts?
 

cujet

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I will try to take a pic of the LED through the welding lens. Also a pic with it off. I don't have a photo hosting service. Can I upload the pics to this site?
 

kj2

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I will try to take a pic of the LED through the welding lens. Also a pic with it off. I don't have a photo hosting service. Can I upload the pics to this site?

I mostly use Tinypic. Photobucket is also possible.
 

cujet

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Thanks for the tip, I'm trying Imgur.

Here is a shot of the LED on full bright, with a #9 gold colored welding lens over the beam. You can clearly see the odd pattern inside the emitter. And, the lines of internal LED's

Here is what was said about the SST-90 LED when I purchased the light: ""About the Luminus Phlatlight SST-90 LED:
The name PhlatLight is derived from Photonic Lattice. Photonic lattice technology creates true surface emission from the source, which enables large area LED chips with uniform brightness over the entire LED chip surface""

http://i.imgur.com/9Nvjzx2.jpg
9Nvjzx2.jpg
 
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cujet

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So, it looks like my LED is going bad.

Where do I get a proper replacement, how to select bin and so on? If I remember correctly, this is an SST-90 LED (or something similar) But the specs I look up are not even close to the SR-90 specs and color temp.
 

cujet

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I wrote the tech support folks at "luminus" and this is what they said:

"Based on the pictures you sent it appears that the emitter in your system is an SBT-90. It also appears that it is exhibiting a transitory issue that we have encountered previously. What is likely occurring is some volatile organic compounds (VOCs) have found their way onto the surface of the LED die. There can be a number of causes for this, very often due to outgassing of adhesives in the system.

Paradoxically the resolution to this issue is usually simply running the LED for more hours. 30 hours is a very small number of hours for the SBT-90. I would recommend running your light continuously for a few days at maximum brightness.. This will "burn off" the VOC's and the emitter will return to normal use."

2qA8kjJ.jpg


Nope, it's an SST-90 according to the picture. Not an SBT90
 

cujet

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Well, the LED finally completely failed. After reading about VOC's and what happens under the silicone dome, I do believe the problem was classic VOC related degredation, possibly creating hot spots and eventual failure. The light came with a 5 year warranty, and it's still in warranty. We shall see if OLight honors the warranty. I will try to post a pic of how it looks now. It's gnarly brown.
 

cujet

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Update: After the Emitter completely failed, I sent the SR90 back to Olight in late May, they got it back to me sometime in August. I was gone the entire month, so I can't say exactly when. I suspect about 2 months turn time.

Anyway, they clearly installed a new LED emitter in it. The glass and reflector are perfectly clean and the focus is perfect. I'm very happy with Olight's customer service and the fact that they honored the warranty after all this time.

I suspect the LED is less bright than the original, however, the focus is better. The end result is that it performs very well and I am very pleased. It also does not seem to get quite as hot. Clearly, it's not as dazzlingly brilliant when shined inside on a white wall as it was before. My particular model was rated at 2200 lumens when new. I notice that the newer ones are 1700 or 1800 lumens. A slightly lower rating.

It's possible my original LED was overdriven as it did lose intensity over the 30 or so hours use on it. I suspect the new one will be more stable.

As far as throw, it seems the same. I can illuminate trees on the other side of the airport without trouble. What more do I need?

Happy!!!
 
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