Strange "burn mark" on P60 dropin

hi guys,

this is a picture of my Solarforce P60 Cree Q5 dropin. I've been using it in a Surefire 6p with a total runtime of maybe 6-10 hours.

Now I discovered this strange burn mark directly on the emmitter. It is still working, but maybe the tint shifted a bit to the greenish side...
Any idea what this is all about?

did you use primaries?

yes, Panasonic (Japanese/US made) CR 123a exclusively

hmm, that should be fine. Was the droppin used continusly for a long time?

that means you emitter is as good as burned emitter.
get a Q5 emitter on a 14mm pcb ( DX has it ) and you can swap it yourself.

No, that's the strange thing about it, the longest burn time was for maybe 20 minutes. So far I liked this dropin a lot. Great throw, lots of lumens..,:mecry:

Oh well I guess that means investing into an Malkoff M60, or the next best thinh to come...

I'm not really into swapping emitters myself, but thanks for the hint anyways

That's interesting. It's hard to believe it still works reasonably well with a big burn mark like that. It's over-heated somehow - maybe the emitter came loose from the heat-sink.

You would be justified in sending it back and asking for a replacement. Alternatively, you could run a comparison with an equivalent unit - it would be interesting to chart its progress to eventual total failure.

20 minutes??... Sounds like a defective emitter. I have a solarforce R2-M and I've let it run for 40 minute stints and it does just fine:thumbsup:. It gets very warm too. I think you should request an RMA with the retailer. If they deny your request, fix it yourself with a Q5 or R2 emitter on a 14mm board.

I had an emitter do that once on one of the more expensive KD lights. The tint shifted to yellow, it got a LOT dimmer, then a brown spot appeared in the middle of the beam, and I junked it. Total burn time <10 hours.

Just a quick update:
I let it run some more, about 30 minutes. It got pretty hot and now its very dim, even with fresh cells and the brown burn mark got even bigger. Very yellow/green tint now and maybe 40 lumens:sick2:. I think it'll be copletly broken soon.

Already cotactet the seller about a replacement, hope i get lucky (Hongkong based ebay seller)...

Same old, same old: IT HAPPEND AGAIN :shakehead

http://img29.imageshack.us/gal.php?g=p1000519n.jpg


Exactly the same symptoms this time with a Solarforce R2 single mode dropin which I got as a replacement from a different seller. (Turned out the seller of the wasted Q5 dropin was willing to replace but requested me to send the broken dropin to him which was no more cost effective to me)

This one had even less total burn time (under 10 hours total) and was used for 2-3 one hour runs (constant on) for searching buildings. Then all of a sudden within one battery run (intermitted usage) the beam turns yellow/greenish and gets very dim fast (brown burn mark can be seen agin on the emitter).

The funny thing is I even wrapped the dropin thightly with aluminum foil and even used artic alumina thermal compound for an absolutely snug fit within the Surefire 6P I was using it in to achive maximum heat transfer to the 6Ps body!

Is this just bad luck, are the Solarforce dropins just no good after all (as long as it worked both of them were great)?
At the moment I'm wondering whether there might be something wrong with my 6P. Is this possible?
I mean there are no electronis in a 6P so could there even be something wrong? (I bought the 6P specifically for LED usage so I almost did'nt run it with the incan P60)

I just depend on my light and can't have any premature failures any more!
Malkoff M60 after all?

Any ideas?

I've seen a lot of those 1 mode dropins go out and I've never heard of one problem.

The solarforce R2 drop ins are some of the brightest traditional reflector modules available. They are over 200 lumens OTF. To get that much light out they have to drive the LED into the ~230 emitter lumen range, which is very hard given the thermal limitations of the 6P as a host.

I think your ~3 hour run time is pushing the thermal limits of this design. I am surprised its lasted this long (almost a year since your original post) under those conditions. Foil wrapping only goes so far. I think you should give Gene malkoff a call and have him recommend one of his products for your 6P. The M60WL would be my recommendation. The color tint and side flood on these modules is superior... to the point that the color resolution to some extent offsets the lower lumen output.

I'm just hesitating with the Malkoff because I fear there might be something wrong with the 6P.

m1ruf said:

I'm just hesitating with the Malkoff because I fear there might be something wrong with the 6P.

Click to expand...

There is absolutely nothing wrong with your 6P host.

I can assure you it is the cheap drop-ins.

Buy a malkoff, you will cease having problems.

The 6P is just a chunk of aluminum and nothing about it could cause the problems you have had.

m1ruf said:

I'm just hesitating with the Malkoff because I fear there might be something wrong with the 6P.

Click to expand...

the 6P is a hollow aluminum shell. There is no way it could do this to the LED. It looks like the phosphor coating on the die burned from the die overheating. the die probably had poor attachment to the substrate through a bad thermal epoxy bond. Replacement of the module will fix the problem. Lack of quality control of the module you bought is the general issue. You can buy the Malkoff and not have to worry about such things.

:wow:
weevils aside...that's burnt phosphor, only way that could occur being focused primary at the center is if the emitter die is thermally disconnected from the heatsink slug immediately below the phosphor cap. Defective indeed!

Thanks for the clarification! I was pretty sure it could'nt be the 6p itself...
And now: Malkoff M60 is on order

m1ruf said:

And now: Malkoff M60 is on order

Click to expand...

You surely wont regret it, Gene makes a wonderful Dropin.

m1ruf said:

I'm just hesitating with the Malkoff because I fear there might be something wrong with the 6P.

Click to expand...

Your fears are unfounded. As has already been pointed out, it's a chunk of aluminum with a very simple switching mechanism. Less the light module, there's not much to go wrong in it.

Malkoff modules take a very traditional approach to heat sinking (a big beefy chunk of brass) and conform well to the head of the 6P for thermal contact, so they should also cope very well with your long runs of on-time.