BLF GT official support thread [FAQ updated 11 Jan 2018]

Jeez David, what strap wrench did you use?

Knowing the person I borrowed them from they would be mid priced, not top quality but they were all metal so not cheap either, all I have to do now is ask that person what I owe him to buy two replacements :money_mouth_face:

I will find a way, even if I damage it more :smiling_imp: I got it to mod which I cannot do if I can’t get into it.

Cheers David

Maybe we need to replace the o-ring against the glass with something that has less friction. A silicone o-ring?

Maybe we can coat the O-ring in something slippery that won’t dry up?

Now I have found a dead led-die on my gt. I can see it with my eyes if I look to the LED at the lowest mode.
Is this the first DOA-GT?
Thats hard to check for Lumintop and to notice that fault.

Here you can see the spot at a distance of 1.5m:

I put a lens on the GT to show the LED better:

And here you can see, what the lens is projecting:

That’s very strange. Since the xhp35 is 4 dies wired in series. If one die loses power, they should all turn off.

Do you think maybe a dark piece of dust or debris landed on the die and then got burned up?

Now it may be blocking light output.

Well if one of the four dies is less efficient you geht less light for the same current.
Maybe it was on the edge off the spec when Cree selected the four dies?

Well, it is sure not nice, but dead on arrival?

Versuch mal die LED direkt zu fotografieren, unterbelichtet und mit nem ND-Filter

Very strange indeed, this is also the first I have heard of any major issues with any GT so far. Everything else have been minor things.

Like they said, it is very strange that 1 die would burn out while the rest still work. Can you get a picture of the LED itself? Maybe on moon mode as well.

It is hard to make any good picture with my Nokia 808 PureView Cellphone. But I made some.
I did not have an other camera, only a small old Exilim EX-H10, which makes worse pictures as my cellphone. It has only a small 12MP CCD-Sensor. My Cellphone-Sensor is 1/1,2” big CMOS with 38MP.





Last two pics with the same orientation. You can see the bonding wires.

That is definitely a faulty die in the LED.

I have had the same thing happen to other quad LED’s and the XHP35’s too, but only in Moon light level/mode, anything higher all 4 dies worked…

Try looking at it at higher power through a welding protection glass if it is powering up at higher level.

I see it in higher levels too. I can see the dark edge in the Hotspot, so no need for welding glass.

Bummer Man!

Noticed something else with your centering ring bar too…

All Centering rings in the production lights has this big hole. Only the prototypes had a good fitting centering ring.

That’s not true.

They were changed to the larger hole sometime after production started. It was discussed many pages back in the main GT thread.

Here’s a tip for removing the bezel. Loosen the upper head from the light engine section first, this takes pressure off the o-ring on the glass and makes the bezel much easier to turn due to less friction.

Why didn’t I think of that sooner. Duh. :wink:

Jason is there some shots of the Gt in bits, as in the whole thing? I have seen the ones with the carriers all in bits, but the head is in 1 part. If there are some, may be useful to pin them to the 1st post for those of us yet to battle opening it. I’m sure I saw some in the depths of a thread….
I’m waiting for the new led’s before I’m even trying. I suppose they will be some months off yet? (I read Lumintop may do something ?)

I checked and I don’t really have any good shots of the head taken apart. I’ll work on finding some and add them to the main GT thread post #3 with the other pictures.

Does this help?

I added it to the GT thread.