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My 2.6w 445nm laser problem (not powerful anymore)

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Hello everyone.

I was bought 2.6W 445nm laser from Blord 5 years ago. Yesterday there was no problem -powerful beam and burning power etc- but after that, I recharged all 26650 batteries and putted it. Beam was so weak like maybe 50mw or something. I tried different batteries and all of them are same. So the problem is not related to my batteries. Like my recharged battery damaged to my driver or diode. But I dont know.

I am waiting for your helps. Thanks.
 

paul1598419

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Sounds like your laser diode LEDed on you. It happens. It likely has an NDB7875 TO-5 diode in it. You can take it apart and isolate the driver to see if it is still putting out ~2400 mA. It would have a three watt output if it had a single element short focal length lens like a G2. It likely is using the cheaper three element lens which would account for the 400 mW loss that you had from the beginning.
 
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Sounds like your laser diode LEDed on you. It happens. It likely has an NDB7875 TO-5 diode in it. You can take it apart and isolate the driver to see if it is still putting out ~2400 mA. It would have a three watt output if it had a single element short focal length lens like a G2. It likely is using the cheaper three element lens which would account for the 400 mW loss that you had from the beginning.
Thank you sir.

I dont have any electrical test device like voltage meter etc. But I can buy it if it is necessary. So what should be my next step? Blord (dealer) is kind of retired, he is not here anymore so I can't contact him. Actually for a few years I did not follow this forum too, until now.

These are my laser's specs by the way:

Diode : 445nm M140
Output diode : 2590 - 2650mW arround
Output boost driver: FMT DRV v2 boost driver 1.8A-2A.
Lens : G2
 

paul1598419

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I have found the M140s do better in the long run limited to 1800 mA. They have become quite inexpensive since you bought this laser. If you are going to adjust your driver you'll need a dummy load to use in place of the laser diode. Trying to adjust the current on a laser diode is a great way to lose another one. If you don't know how, I can give you the way to build and use one.
 
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I have found the M140s do better in the long run limited to 1800 mA. They have become quite inexpensive since you bought this laser. If you are going to adjust your driver you'll need a dummy load to use in place of the laser diode. Trying to adjust the current on a laser diode is a great way to lose another one. If you don't know how, I can give you the way to build and use one.
Actually I dont have any technical information on lasers. I am already interested PC overclocks and hardwares only. So I dont know if I can.

There is any compataible new diode for my driver? Can I use ANY 445nm diode, or may I get new m140?

Sorry for noob questions btw.
 

paul1598419

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If it had an M140 diode in it, you might want to try that again. I have built many of these lasers driven at 1.8 amps and they all output ~2+ watts using a single element short focal length lens. 2.2 watts has been the top of the mark on these builds. There is a larger diode, the NDB7875, which is 9mm as apposed to 5.6mm for the M140. It has the same divergence specs as the M140, but can be driven harder than it. They have been discontinued, but still can be found if you look.
 
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If it had an M140 diode in it, you might want to try that again. I have built many of these lasers driven at 1.8 amps and they all output ~2+ watts using a single element short focal length lens. 2.2 watts has been the top of the mark on these builds. There is a larger diode, the NDB7875, which is 9mm as apposed to 5.6mm for the M140. It has the same divergence specs as the M140, but can be driven harder than it. They have been discontinued, but still can be found if you look.
So 2.6W was too much for mine m140, right?

I will research about NDB7875. Maybe I can find technical guy on this forum and will ship it.

Thank you sir.
 

CurtisOliver

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NDB7875's are less temperamental and will give you better output power. Your M140 was being overdriven.
 

paul1598419

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So 2.6W was too much for mine m140, right?

I will research about NDB7875. Maybe I can find technical guy on this forum and will ship it.

Thank you sir.
If that laser was truly 2.6 watts it was very much over driven. Did you measure the output yourself, or was that the claim when you bought it? I really don't see an M140 lasting very long at 2.6 watts. I have built a dozen lasers using this diode and 2.2 watts is the top of the mark.
 
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If that laser was truly 2.6 watts it was very much over driven. Did you measure the output yourself, or was that the claim when you bought it? I really don't see an M140 lasting very long at 2.6 watts. I have built a dozen lasers using this diode and 2.2 watts is the top of the mark.
It was claim. I didn't test it.

So, currently I am looking for NDB7875 diode. But as I said, I have no technical information. When I buy it, simply two solder and done. Without any voltage/output adjustment, will it works fine? I mean 1.8-2.0A is OK for NDB7875? Or need I buy voltagemeter and dummy load?
 

paul1598419

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The NDB7875 is a larger diode than the M140. You should have no problem with driving it with your driver as long as your driver is still good. You will need a new 12 mm module to press this diode into because it is a larger diode and it has only two leads, unlike the M140 which is smaller and has three. I drive my NDB7875s at 2.4 amps. This will give you a much greater output power of 3 watts. You can always just use another M140 as you don't know how much power it was putting out or what current it was driven at. I normally drive M140s at 1.8 amps. This will give up to 2.2 watts out.

The problem you have is you just don't know what you were getting out before the diode died, nor do you know what current the driver is set to. If I had your laser in front of me, I would check the driver to make sure it is still working and to find out what current it is set for. Knowing that, I would then proceed.
 

hakzaw1

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I would suggest that you do NOT try to fix this.. instead ask until you get a VET member willing to rebuild it for you .. post a request for help in this thread and/or a new one in this same section .
 




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