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Need help with disassembly

maggot

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I have a 1.2 - 1.4 watt blue laser in a gatling housing. When I received it, the negative terminal spring was bent, and after swapping batteries a few times, it bent to the point where it is resting on the inside wall of the host (pic #4). I emailed pics of the problem to the seller and voiced my concern about it shorting out, and now I have a free replacement in the mail and I get to keep the old laser.

I bought some protected 16340 batteries, and found that when inserted the spring compressed enough to no longer be touching the inside wall. However, the last time I inserted batteries, when going to screw on the tail cap, I accidentally touched the side of the cap to the positive battery terminal and the host, causing the laser to turn on briefly. Unfortunately, I believe the spring didn't have enough pressure to pull itself away from the inside of the host when that happened. After I finished screwing on the tail cap, I turned the laser on. It ran about 7-10 seconds, then died. After taking the batteries out, the inside of the laser smells like burnt electrical components.

I was able to slide a paper barrier between the spring and the inside host wall, unreasonably hoping it was a short that was keeping the laser from powering on, but to no avail. Now I'm hoping it's just the board that is fried but the diode is still good.

My problem now is that I can't figure out how to get the components out of the host. I don't see any threading for the components to screw into, so I'm assuming they are pressed in. Is this correct? Might it be glued in place, as I can see some sort of black substance on the inside seams between the component's housing and the host, or might that be some sort of thermal paste? I have tried gently tapping out the components from both ends, but nothing seemed to move. I was afraid to tap very hard in fear of damaging the diode which I'm hoping is still good.

I searched the forums for disassembly pictures / instructions. I found some pics from a few years ago that showed the host being in two pieces (after you remove the 12 rails), but it appears I have a newer model that is all one piece. I also couldn't tell exactly how the component housing was mounted inside the host.

Any information on how to disassemble this thing would be greatly appreciated. If it's pressed together and I need to bust out a hammer and punch, I can do that. If doing so might damage the potentially good diode inside, but that's the only way to get it apart, so be it. I'd just like to know I'm doing the right thing before I start hammering away.

Thank you for any help you can give on the matter, and thank you for the highly informative forums.
 

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Sta

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Welcome to the forum!
I don't know that much about this particular host, as I don't own one, but I wouldn't recommend any hammering. The diodes used inside are typically as cheap (and thus low-quality) as possible and most likely won't withstand the shock.
 

ElectricPlasma

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Not necessarily cheap diodes Sta, at least not anymore. The more recent ones use more modern and "well known" diodes, but I have the same host but with the old diode. But still, I agree, don't bang it with a hammer :p

From looking at mine it looks like tube things going across the host can be unscrewed with some sort of hex bit, but you'll have to look around a hardware store for that. Also I can see a separation or seam between the battery bay and the module, that looks like it can somehow pry apart once the tube things are off.
 
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maggot

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Thanks for the replies.

Yea, getting the 12 tubes removed was the easy part (2mm hex head). From what I'm seeing, the newer host is all one piece. I saw pics of the older host, and it definitely separates in 2 pieces. If it did come apart that way, I might be able to access the guts of the laser without removing the inner assembly that seems to be pressed in. Unfortunately, I'm not that lucky.
 

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GSS

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Thanks for the replies.

Yea, getting the 12 tubes removed was the easy part (2mm hex head). From what I'm seeing, the newer host is all one piece. I saw pics of the older host, and it definitely separates in 2 pieces. If it did come apart that way, I might be able to access the guts of the laser without removing the inner assembly that seems to be pressed in. Unfortunately, I'm not that lucky.
With all hope of you fixing it, i'm seeing with all the tubes removed it looks alot more comfy to hold and handle as others have mentioned it is kinda weird to the hand. Looks good that way also. I can't see those tubes helping with heat but could be wrong.
Good luck with figuring it out:)
 
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maggot

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To me, it feels worse in my hand with all the tubes removed. The longer part of the host isn't long enough to grip it comfortably. Plus there are lots of semi-sharp edges exposed where they didn't deburr the machined holes.
 

Antharak

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I have both new and old units and the new one is a press fit. There should have been a rubber bushing around the (-) contact. I would try to see if the seller will replace it as it was not complete from the start.
Ed
 

maggot

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There is a rubber bushing around the negative contact, but it sits at a 45 degree angle, so it really only covered about 1/2 the open area. I have since moved it farther to get a better look at the inside.

I have a new one on the way already, and they let me keep the defective unit as well. All I'm looking to do now is get the old guts out of the host so I can put something else in it.

I think I'll just give up on trying to preserve the diode since it may very well be toast already. I've also come to the conclusion that the black stuff around the pressed in unit is some sort of glue. I was able to scrape some out and it is like no thermal paste I've ever seen. It's way to tough and rubbery.

I think I might try spraying some gun cleaner inside and dissolve as much glue as I can before I try to hammer out the guts. If I totally destroy whatever is inside in the process, I'll have the same thing I have now, a broken laser. And since a replacement is on the way, I'm effectively working on a broken laser that I picked up for free, so no loss.

Thanks for your input and I'll be sure to post my results when I have them.
 
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maggot

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VICTORY!

So I decided to spray a tiny bit of gun cleaner around the inside edges of the heat sink to loosen up the glue. I used a set of long, sharp point tweezers to jab the cleaner as deep into the glue as I could, plugged up the end to keep it from evaporating, and let it sit for two hours. After that I was able to tap it out with a center punch and hammer with 8 moderately firm hits, four on one side, then four on the other. I tapped it out while it sat on a small board that was on my lap to try to minimize the shock, trying not to damage the diode that's most likely toasted anyways. I was kind of surprised that it came out as easily as it did. The disassembled pieces and the tools I used are in the first pic.

The rubber bushing around the negative contact spring was 1/2 melted on the inside. The black / burnt crap on the end of the pcb is residue from that. The solder point for the negative contact spring had completely failed. The only thing keeping it in it's hole was a bend in the wire. I'm wondering if the resistance from that failing solder joint produced enough heat to melt the rubber bushing, or if it was from to much contact with the board since it was originally installed at about a 45 degree angle. I'd like to think it didn't melt from leaving it on too long. The manufacturer said for ever 2 minutes on, give it 30 seconds off. I never ran it longer than 90 seconds max on a few occasions. Leaving it on that long it would start to warm up, and I'd always wait for it to cool down to near or at idle temperature, which usually took about 5 minutes. So my nastiest duty cycle would be 1.5 minutes on, 5 minutes off.

It looks like my next step is to clean up that board, resolder that joint, and see if anything still works. I do have 2 more questions though.

1. Where is the positive terminal? I'm assuming it is running through the heat sink since that was the only part that made contact with the host, and I know the host body is part of the circuit (like a flashlight or mechanical e-cig).

2. How do I unmount the diode from the heat sink? Is that pressed in as well?
 

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maggot

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And now for the final results.

After resoldering the negative contact, it still would not power on. I wasn't able to read any activity from the driver board at all, so I unsoldered the diode and hooked it up to a different power supply. Low and behold, the diode still lives! I feel like that's rather remarkable after all it's been through. Now all I need to do is find a suitable replacement driver and I'm back in business (any recommendations?). Plus, I have a replacement laser in the mail on it's way to me already. It took a days worth of work but in the end I'll have 2 lasers for the price of 1 + a new driver.

Thanks to all for their input and thanks to all again for the forums!
 




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