LT-20W-A laser module not emitting light

[laurent.duvalier12345]

Good day ,
I am new in this forum and i need your help.
I bought yesterday a laser module from laser tree model : LT-20w with 4W optical output ,it was working fine when I connected the adapter to 12V.
by mistake I used 29 V 0.75 A adapter instead of 12 V and now the laser not working and only the cooling FAN is spinning .

Could you please help me to check if the laser module is dead.
Thank you in advance.

 

[RedCowboy]

You can remove the driver and test the laser diode with a single 18650, you MUST get the polarity correct or you will blow the laser diode if it isn't already, however you likely killed the driver, so test the laser diode and if it's good then replace the driver.

 

[laurent.duvalier12345]

Thank you very much for your fast reply
Do You meen that i need to connect the LD+ AND LD - to a 3,7V battery

 

[RedCowboy]

If you can remove/disconnect the driver from the laser diode, then you can test the laser diode by, making certain the laser head is pointed at a beamstop/backstop/brick ( safe direction ) and test the laser diode with a single 18650 which lacks the voltage to over power any of the blue laser diodes, however it will light up reasonably bright if it's not blown.

If the laser diode tests GOOD then replace the driver.

 

[laurent.duvalier12345]

If you can remove/disconnect the driver from the laser diode, then you can test the laser diode by, making certain the laser head is pointed at a beamstop/backstop/brick ( safe direction ) and test the laser diode with a single 18650 which lacks the voltage to over power any of the blue laser diodes, however it will light up reasonably bright if it's not blown.

If the laser diode tests GOOD then replace the driver.

Thank you very much for your help,
unfortunetly the diode is blown , i tried to test it several times with the good polarity but it does not emitting any signal .
I already remove it from the module.
could you please tell me if it possible replace it or i have to buy new module. ?

 

[RedCowboy]

I would replace the laser diode because I have many on hand, however I don't know which diode you unit uses, it says 4W and power consumption or supply rather is 12V @ 1.6A so it could be a ndb7A75 or the variant used by Chinese industry, but I don't know if it's a FAC enhanced diode or not without looking at it, you might be better off buying another unit since the driver is probably blown too. What did it cost ?

 

[laurent.duvalier12345]

I would replace the laser diode because I have many on hand, however I don't know which diode you unit uses, it says 4W and power consumption or supply rather is 12V @ 1.6A so it could be a ndb7A75 or the variant used by Chinese industry, but I don't know if it's a FAC enhanced diode or not without looking at it, you might be better off buying another unit since the driver is probably blown too. What did it cost ?

Thank you very much for your reply,
I bought the laser module yesterday for 150 $, The unit uses LASERTREE Diode Laser bleue, 450nm, 4W TO-5, 9mm
that is quite expensive between 50-60 $ .
Unfortunately The solution is to buy a new one.
Could you please advice for a good quality laser cutter/engraver.

​

​