Title says it all. Bought a laserbtb (FDA) 300mw 532 nm. 2 days ago it lit a match in 1 second. Now it can't light one in 60 seconds. I am really desperate! What's going on? Batteries are fully loaded and laser is focussed out all the way like it is done to burn things......
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My laser doesnt burn anymore all of a sudden
- Thread starter BotoX
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Try refocusing
-Danny
-Danny
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yes....
yes....
that did not work. I tried 5 times, still not able to burn. what the hell... :S
What I also noticed is that if I defocus all the way (for burning) I can see a rectangle instead of a round point. already at 30 cm. maybe that's the problem?
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Sounds like your lens is in backward. Have you had your lens out?
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There are many possibilities. You might have a contaminated lens. Dirt or other film may have deposited on the lens. Was the unit hit or dropped? This could misalign the crystal set with respect to the IR diode. There are too many variables to know from what you have said here.
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Not sure what you meant by twisting the focus ring out and in all the way, but here's generally how you focus it correctly.
You're gunna want to use laser safety goggles to do this so that you only have the dot indication and not the huge amount of light that will wash it out, point your laser around 5 inches away from the match. To focus it, you're going to want to turn the focus ring either direction until you get the smallest dot possible. You can try doing this on a larger flat surface (careful, it might burn if you're successful so try a cardboard box or something you don't need) and then once you get the dot, put the match in front of it. Make sure the smallest point of the beam hits the match. Your beam should look something like this:
Where F is the distance between the laser aperture and focus point, the far right arrow of F should be where you put the match.
You don't see it quite in that detail, and depending on your environment you may not even see the beam at all.
You're gunna want to use laser safety goggles to do this so that you only have the dot indication and not the huge amount of light that will wash it out, point your laser around 5 inches away from the match. To focus it, you're going to want to turn the focus ring either direction until you get the smallest dot possible. You can try doing this on a larger flat surface (careful, it might burn if you're successful so try a cardboard box or something you don't need) and then once you get the dot, put the match in front of it. Make sure the smallest point of the beam hits the match. Your beam should look something like this:
Where F is the distance between the laser aperture and focus point, the far right arrow of F should be where you put the match.
You don't see it quite in that detail, and depending on your environment you may not even see the beam at all.
Last edited:
Richie89
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Hmm possible Crystal unaligned by dropping it? Pump somehow messed up? Or left it on way past duty cycle? 
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Test the batteries, and adjust the focus as ElectricPlasma explained. Maybe try bypassing the tailcap, or at least make sure the pin is inserted all the way.
Make sure the safety shutter is not partway closed.
To make it easier to see the beam for focusing, turn off all other lights, and have the beam terminate on something matte and black.
If with that done you're still not able to light a match, you'll need to send the laser back to Sky. It is probably a misaligned crystal, and sometimes it happens even without a laser being dropped, or left on too long
Make sure the safety shutter is not partway closed.
To make it easier to see the beam for focusing, turn off all other lights, and have the beam terminate on something matte and black.
If with that done you're still not able to light a match, you'll need to send the laser back to Sky. It is probably a misaligned crystal, and sometimes it happens even without a laser being dropped, or left on too long