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Possible Dead Laser

maxxdout

maxxdout

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So I was using my eBay 5mw laser at a party today. At first, it didn't work too well, it was acting as if the batteries were dead. It was slightly cold out, also(50-60F). I warmed it up in my hands and it was still acting weird, but occasionally, I could get a good beam (was shining it in smoke). This beam could last anywhere from a second to up 20 seconds.

Now that I've got home, I've switched the batteries around a few times, and the laser is barely working.

The weird thing is, I can see a small red dot coming out of it. If I look down the laser (yea I know, stupid thing to do), I can see a small flash of green, and then all I see is red again.

This laser is about 3 weeks old, have been using it on/off for the past few weeks (maybe a total of 2 hours at the most, not using more than 5 minutes each time.)

So yea, is it a possibility that my laser is dead? I'm going to try out some different batteries in the meantime...

Thanks!
 





IsaacT

IsaacT

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"If I look down the gun, I can see a small flash....."

^^That is the explosion from the bullet....

On the actual topic tho, do you have any pics of the laser, or a link? What kind of an on/off switch does it have? Have you ever reversed the polarity on it?
 
IsaacT

IsaacT

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It is entirely possible that putting the batteries in backwards shortened the lifespan of your diode considerably....you are probably lucky it didn't die then....but ignoring that....how sturdy is the button switch on it? Because I have a cheap <5mW red pointer that has a sort of short in the button to where I have to press the button hard and at the right angle, otherwise the beam comes and goes as the electricity comes and goes due to the bad connection.
 
maxxdout

maxxdout

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I didn't think of that. The button seems to have a nice "click" and it doesn't get brighter/dimmer by how much force I apply to it.

If I could remove my driver board and everything from it, I would, but this laser is weird because it doesn't have anything "sticking out" under the cap. The only thing I can remove is the lens, it unscrews from the inside.
 
IsaacT

IsaacT

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If the "click" is nice and the crisp, then the button probably isn't the problem....honestly I imagine that the initial reverse polarity coupled with the fact that it is from eBay(nothing against them but its a gamble) is your problem....I could definitely be wrong though. Sorry to hear about your laser troubles, I know the feeling as my 50mW Greenie has a malfunctioning tail cap. Good luck.
 
maxxdout

maxxdout

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I'm going to try out some new batteries tomorrow.

If the batteries don't work, I'll officially call it dead and try to tear it apart :p

All in all, I think I got my $7 worth ;)

EDIT: HAHA, wow. I just raided my stepdad's flash lights and found some AAA's. It seems to have been my batteries, because it powered up no problem with those AAA's from his flashlight :p
 
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AdamCaudill

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maxxdout said:
The weird thing is, I can see a small red dot coming out of it. If I look down the laser (yea I know, stupid thing to do), I can see a small flash of green, and then all I see is red again.
Click to expand...

The red you are seeing is from the IR pump which is barely in the visible spectrum (depends on your vision as yo how far into IR you can see). Because IR ranges from almost invisible to completely invisible, you have no idea how much power is hitting your eye. It is possible to do permanent damage to your eyes and you won't notice it till it's too late.

Also, in the conversion process from 808nm -> 1064nm -> 532nm there is a fairly significant loss in output. So the pump is putting out far more than the final output. Just because a laser is marked <5mW doesn't mean you can't be hurt.

No matter what, never look directly into a laser. You only have one set of eyes, remember that.
 
maxxdout

maxxdout

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Never knew that, Adam. I figured that if there was barely anything coming out of the aperture, I would be fine. My eye sight still seems the same, but I will remember not to be a dumbass again and look into the laser :p
 
AdamCaudill

AdamCaudill

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If the batteries were that low, you're probably fine and no damage was done.

IR light is rather dangerous because you don't realize that it's there. I have a laser that emits a barely visible tiny dark red dot, looks to be weaker than a 1mW red cat toy; in reality it's 300mW. If you don't know what you are looking at, you can get hurt in a hurry.
 
AdamCaudill

AdamCaudill

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maxxdout said:
Well it's a good thing that mine is only 5mw and not 300 :p
Click to expand...

It's closer than you might think ;)

From the reading I've done, it seems those lower end "5mW" greens are pumped by a ~200mW 808nm diode. That pump diode is what you really have to worry about.
 
maxxdout

maxxdout

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Really? I now understand your previous post a little better now. So these cheap lasers come with a powerful diode, but in order for it to be visible, it is converted and in that conversion process, the power drops drastically?
 
qumefox

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I have a handful of those greens now. pretty much all of them are extremely picky about temperature.

There is also no way to get the module/driver out without destroying the housing. They're pressed in apparently. They're pretty much bottom of the barrel, as far as quality goes. If you want one good one, you should buy a dozen and hope you get lucky... or just buy a decent laser from a reputable vendor.

Now the 405nm version that looks identical.. those are well worth the $10. Usually 30-50mw and being just diode lasers.. there's not a lot to screw up QC wise.

It IS technically possible to 'fix' them.. but they won't be in the same host. I totally tore a module apart on one, realigned the crystal block and OC, and got 36mw of green(used IR filter) using only the stock parts out of the pen other than the IR filter. Though it did take me over 8 hours to get a beam out of it again after tearing it apart...
 
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