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

Texas_Ace · May 22, 2021, 4:46pm

YouFunnyGuys:

My BLF GT is not turning on.

I have tried to search these forums and also Google and Bing with no joy.

I purchased from original buy thread on these forums. Received around February 2018.

Batteries are fully charged

Button lights up and responds to presses properly (I think)

Going through the reset steps in the manual does seem to work as far as the flashes on the button are concerned but the LED just will not turn on.

Re-seated the end cap and head multiple times.

Battery Orientation is correct

Batteries are freshly charged and also close to brand new

Also tried different brand new batteries

NEVER dropped or physically mishandled

NEVER driven at full power for more than 2 to 3 minutes, typically 10-15 seconds at a time during dog walking.

Apologies if this has been addressed and I just suck at searching.

Thank you!

Hmm, sounds like either a wiring issue to the LED, a bad driver or a dead LED.

Can you see any black spots on the LED? or signs of damage?

You will need to remove the driver and see if there is any burn smell or signs of damage there. If not then next step is to test the LED, you can connect a 12v source (could use the carriers with some wire if needed) to the LED wires directly for a moment to see if it lights up. Only do it for a second since it will be driving it with too much power for extended use.

Also make sure polarity is correct, if put backwards it can fry the LED.

If the LED lights up directly then it is a driver issue, if the LED does not light up, then most likely a dead LED or possibly a short to the reflector. You will have to remove the head to do further testing.

YouFunnyGuys · May 22, 2021, 5:25pm

Thanks for the prompt response

None. Yellow as can be. Clean, no signs of burn or other damage

No action I used both a bench power supply and the actual battery pack. The pack is putting out about 16V as measured with a multimeter.

Now, how to disassemble or replace the LED? Any guides? Or is there a warranty/repair service?

Thanks again for the help

Texas_Ace · May 22, 2021, 5:49pm

YouFunnyGuys:

Texas_Ace:

Hmm, sounds like either a wiring issue to the LED, a bad driver or a dead LED.

Thanks for the prompt response

Can you see any black spots on the LED? or signs of damage?

None. Yellow as can be. Clean, no signs of burn or other damage

You will need to remove the driver and see if there is any burn smell or signs of damage there. If not then next step is to test the LED, you can connect a 12v source (could use the carriers with some wire if needed) to the LED wires directly for a moment to see if it lights up. Only do it for a second since it will be driving it with too much power for extended use.

Also make sure polarity is correct, if put backwards it can fry the LED.

No action I used both a bench power supply and the actual battery pack. The pack is putting out about 16V as measured with a multimeter.

If the LED lights up directly then it is a driver issue, if the LED does not light up, then most likely a dead LED or possibly a short to the reflector. You will have to remove the head to do further testing.

Now, how to disassemble or replace the LED? Any guides? Or is there a warranty/repair service?

Thanks again for the help

I think VOB had a video showing how to upgrade the GT to the GT70 but it could be applied to your situation as well.

Hardest part is opening the head, you need a strap wrench for that, after that it is a pretty basic LED swap.

YouFunnyGuys · May 22, 2021, 5:52pm

Ah, oh well. I think I’ll sell it as is then I haven’t used a soldering iron or similar in over 20 years LOL.

Thank you once again.

Texas_Ace · May 22, 2021, 5:58pm

lol, up to you, it is really pretty simple to swap the LED, lots of writes and videos showing how as well.

raccoon · May 22, 2021, 6:01pm

Wow, when I Google your location, I can see exactly where you live!

I'm not brave enough to be so specific, but it is cool and different.

Yokiamy · May 22, 2021, 6:03pm

There are enough BLF members in your area who are willing to help you out.

YouFunnyGuys · May 22, 2021, 6:24pm

That’s actually a mine field. Proceed with caution, bad peeps ROTFL.

YouFunnyGuys · May 22, 2021, 6:25pm

Oh wow… any tips on how to go about this? Sorry for the n00b questions.

JasonWW · May 24, 2021, 12:13am

I think Tom E is trustworthy and fairly close. He lives in Long Island NY. You might contact him about sending in the head to swap the led. I can’t say what he might charge or if he’s got the time to do it, but it’s worth asking.

YouFunnyGuys · May 23, 2021, 2:51pm

Thank you, kindly, Jason

FlashPilot · December 22, 2021, 9:34pm

Has anyone found an in-stock supply of XHP35.2 HI in flux bins greater than D4? I hope to find E2 flux bins or greater in 5000-6500K to reflow into my stock GT. Crees data sheets appear to be dated and they are notorious for not listing all available variations. I’ll probably settle for a D4 if nothing turns up. Mouser has plenty in stock and they are easy to deal with.

Still no listings showing for XHP70D-H0 variations (XHP70.3 HI). Id love to try one in a GT with a TA driver, assuming high flux bins once available. Cree’s data sheet looks promising.

I’ll probably cross post this in a few other threads to see if anything turns up…