MagLED drop-in with SSC P4 U-bin LED, dome turning brown

Hi all,
Some years ago, whenever the SSC P4 U-bin emitters were the latest brightest emitter, I purchased one and modded my MagLED drop-in bulb replacement, replacing the Luxeon with the SSC P4.

The light has been off and on from time to time since then and produces a lot more light than the original MagLED. However, I have noticed that the silicone dome or gummy or whatever you want to call it, has started to develop a brownish tint to it. It is still quite transparent I suppose but tinted brown a bit.

Any ideas what could cause this? The tint appears to permeate the silicone, it's not just on the surface. It appears there is more tint closer to the die of the LED.

Is this a sign that the emitter is getting too hot? I can't see any difference in beam tint so far, it's still the cool white color I'm used to seeing. My understanding was that the MagLED drop-in didn't drive the emitter all that hard, and that it used a temperature sensor to down-regulate the current if the drop-in got too hot. Seems kind of strange that the gummy dome would turn brown from heat, if that's what it is...

I would suspect that it overheated. The stock Maglite LED flashlights were never known for even marginally decent heat dissipation.

Seems kind of strange that the gummy dome would turn brown from heat, if that's what it is...

Click to expand...

Yeah...but there is definitely not enough heatsinking, even if there was a temperature sensor (I don't know :shrug. The process has progressed very slowly, I assume.

Or did you leave it for (very) long in (very) intense sunlight? Maybe this is why the silicone has degraded, though I have no experience with it.

Maybe some others will throw in their opinions

Maybe I should leave the light on overnight and see if the gets browner... or goes