unsuccessfull pot mod

hello guys, today i decided to pot mod my green laser pointer 50mw... it was really bad decision...

when i pull a module outside there was written 400mA on it...

then i took little screwdriver and turn a pot.. i was very carefull as it was not my first pot mod... but this one was my first unsuccessfull...

what happend.... i get totally weak dot, then i tried to turn it to other side and i get one big flash {realy bright} and than totally weak dot...
so on one side it is weak on other side it is bright but i cant get CW.. it is working now just like pulse.... i am not able to fix it anymore...

my question is - is my diode dead, or there is only problem with diver, or pot???
it was my best laser i have ever had and now it is gone... it was really powerfull.. i dont know if it war real 50mw output as i dont have any lasermeter, but i suppose that it could be 50mw... it was pen style and even after couple of minutes ON, there was any sign of heat... any....
so i was thinking that i could be able to push it little bit far..
do you guys think that it is dead???
i know that most of you dont reccomend pot mod, but like i sad it was not my first time... i have done it before on each from my 4 laserpointers and it was working perfectly without any problem.. all the time i get unbelieveable results and each of this "pot moded" lasers is still in perfect condition... i could turn it up and down and there was always same response from pot..... so i dont know what is problem here...

cheers

doesn't sounds good, I've never pot modded any of my lasers so IDK what to expect. then again all the lasers i got were high quality CNI lasers or DIY's that didn't need to be pot modded

Well you could have broken the pot it's self, some of those come with glue and they are very small and fragile. Did you hear/feel a crack when you adjusted it?

From what I've learned, the pot is there to lower the current to the LD for optimal crystal performance because depending on the quality of the crystal (the main variable in lasers; power, driver, and diode are usually identical stable and solid, it's the crystals that vary and determine the laser's class/mW) it may not operate in TEM00, or it may even lower the output power by increasing the current. And for the high quality lower power pointers (like Nova X-15) that are designed for lower mW.

In my not so humble opinion, any pot mod is unsuccessful, and a successful pot mod would be to buy a more powerful laser! ;D

If your laser is still outputting even a tiny bit green, then chances are more then likely that your LD is fine, just way under current. If there's no green at all, and using a video camera hooked up to monitor (don't look down the aperture) and you see a tiny bit of light, then the LD could be blown.

1st rule EVER!: Check power source; fully charged batteries

Depending on the drivers adjustable current values, you could have blown the LD if the pot allows you to adjust a good 20-100mA over the diodes rating, but IMO that would be unlikely.

Ace82 said:

Well you could have broken the pot it's self, some of those come with glue and they are very small and fragile.  Did you hear/feel a crack when you adjusted it?

From what I've learned, the pot is there to lower the current to the LD for optimal crystal performance because depending on the quality of the crystal (the main variable in lasers; power, driver, and diode are usually identical stable and solid, it's the crystals that vary and determine the laser's class/mW) it may not operate in TEM00, or it may even lower the output power by increasing the current.  And for the high quality lower power pointers (like Nova X-15) that are designed for lower mW.

In my not so humble opinion, any pot mod is unsuccessful, and a successful pot mod would be to buy a more powerful laser!  ;D

If your laser is still outputting even a tiny bit green, then chances are more then likely that your LD is fine, just way under current.  If there's no green at all, and using a video camera hooked up to monitor (don't look down the aperture) and you see a tiny bit of light, then the LD could be blown.  

1st rule EVER!: Check power source; fully charged batteries

Depending on the drivers adjustable current values, you could have blown the LD if the pot allows you to adjust a good 20-100mA over the diodes rating, but IMO that would be unlikely.  

Click to expand...

Exactly, there DPSS so the crystals are really a big deal and if you try to pump them with more IR from the diode the power will actually go DOWN.
Some people get lucky, some get unlucky and some will flat out lie to you about lasers.

--hydro15

Ace82 said:

Well you could have broken the pot it's self, some of those come with glue and they are very small and fragile.  Did you hear/feel a crack when you adjusted it?

Click to expand...

i didnt have a glue on pot... i dint hear/feel a crack when i adjusted it...

i am able to set a dot for output maybe 2-3mw... :'( :'( it is just my guess.... but i cant set it to the previous state...
i think that there is only problem in a pot...
what i can do with it??? can i replace a driver... it was written on the module 400mA with a marker, so i will problably need some driver adjustet at 400ma.. can anybody give me advice where i can get driver like this for green laser???

The crystals do decide what current is perfect, so you should try to slowly turn it up and down until it works. It might be hard to change the pot while the laser is running. You might want to try to put the batteries in place behind the spring, and put a magnet on the end. If it can go above and below 400mA, then it should be able to get there... You just need to hit that "hot spot".

400th post!

well guys, i was trying to fix it maybe 2 hours... nothing... all the time i was able to hit a spot where it was realy bright but i couldnt stabilize it... it was significant that pot was wrong...

:'( :'( :'(

now the driver is in a bin and module is missing some

I fixed my buddy's laser. His pot was broken after he tried to pot mod it. I carefully unsoldered the pot. Then soldered two wires where it used to be. Attach a standard size 5k ohm pot. Turn the resistance all the way up and turn on the laser. While its running turn down the pot until it starts to lase like before. Turn off the power remove the pot and measure the resistance being careful not to turn it. Unsolder the wires and place a resistor of equal value to the pot on the driver and solder it in place. Put it back together and Walla! Back from the dead.

_________________________________________________

Since you pitched your driver, build a custom one I guess. Or maybe you can find one here.

http://www.roithner-laser.com/Drivers.htm

unless you spent alot of money on the laser, i would recomend getting a new laser. i am one to waist my time on worthless things, so i know first hand how annoying it is to try to fix something that is incapable of being fixed

opto_kev said:

unless you spent alot of money on the laser, i would recomend getting a new laser. i am one to waist my time on worthless things, so i know first hand how annoying it is to try to fix something that is incapable of being fixed

Click to expand...

Everything can be fixed, it depends on what you have more of... Money or time