First build BDR-209

[Pastor of Muppets]

I really wanted to post this on LPF because the people there are the ones who sell the driver and diode I'm using. Unfortunately, the administrators won't approve me.
I have a micro flexdrive v5 that I purchased with the BDR-209 sold as a unit in aixiz housing from DTR's shop and a host from Z80 (Barnett Unlimited). The host came with battery board. I soldered the battery board to the driver leads. Worked fine (outside of the host, for obvious reasons). Then I installed in the host. Nothing. I took the unit out of the host, unsoldered from the driver board (to eliminate host \ board variables) and hooked the driver leads to an 18650: nothing.
I understand that the bare diodes are very susceptible to ESD shock. I understand that the diode being unsoldered to and from the driver board leaves the diode susceptible to ESD as well as damage from a charged capacitor upon hooking back up to driver board. I haven't had the bare diode out and I haven't disconnected from the driver board.
I've only hooked the driver up to a battery and to the battery board. Can a static shock damage the diode THROUGH the driver board ? Or could the driver board have been damaged by static shock ? The only thing I can think of is static shock, as I have purchased the module connected to the driver and didn't mess with anything except the + and - from the driver to the battery board. When the module (connected to the driver, since that's the way I bought it) was briefly tested, it was in the heatsink and was for 1 second, to make sure it worked before putting in the host.
I'm asking for any help in this matter. I don't know how to find what is damaged or understand why it got damaged.
Thank you in advance.

-Philippe

 

[aznsx]

Welcome! Although I'm not coming up with any specific things to investigate (at this point), I just want to ensure that the cell you're testing with has been verified as still indicating a reasonable / expected output voltage as of this moment, and following all your testing. I only ask to ensure that any protection circuitry that your cell might have hasn't perhaps 'tripped' during the process and shut the cell output down.

 

[Pastor of Muppets]

Thank you, aznsx. I am using a protected cell, so I will test others. At this point, I have two concerns: if the diode has gone zombie or LED from static damage, I would have expected some output, however weak. But I haven't blown a lot of diodes so that may be faulty reasoning. However, if the battery is not the issue, I'm guessing I damaged the diode through leaked voltage from my un-grounded soldering iron. I read the whole thread on the diode and I did not notice that the diode was subject to damage after being soldered to the driver, but asking 2 AI's (which I try to avoid doing) it seems that the diode is subject to this damage during any point in soldering the board. So I need to check the driver sense resistor with a multimeter after trying different batteries. I appreciate the assistance. I'm working with the customer service at DTR laser shop, but it's slow to get replies.

 

[dc38]

Thank you, aznsx. I am using a protected cell, so I will test others. At this point, I have two concerns: if the diode has gone zombie or LED from static damage, I would have expected some output, however weak. But I haven't blown a lot of diodes so that may be faulty reasoning. However, if the battery is not the issue, I'm guessing I damaged the diode through leaked voltage from my un-grounded soldering iron. I read the whole thread on the diode and I did not notice that the diode was subject to damage after being soldered to the driver, but asking 2 AI's (which I try to avoid doing) it seems that the diode is subject to this damage during any point in soldering the board. So I need to check the driver sense resistor with a multimeter after trying different batteries. I appreciate the assistance. I'm working with the customer service at DTR laser shop, but it's slow to get replies.

I have 0 experience with lasers, but just a little bit with LED's...is the polarity attached the right way? **also, was there any solder spillover that could've cause a short?

 

[Pastor of Muppets]

I have 0 experience with lasers, but just a little bit with LED's...is the polarity attached the right way? **also, was there any solder spillover that could've cause a short?

Polarity is correct. I tried with the driver connected to the battery board first, and to eliminate another part of the equation, I tried the driver correctly to a few different lipos, protected and unprotected. I used 15x magnifier on the PC screen to check solder. I'm convinced I damaged something from leaked current \ voltage from my cheap AC ungrounded soldering iron. I was under the belief that the diode (a 405nm violet diode, which is the most fragile to ESD) would be protected from ESD once it was in the circuit. Mistake 1. Mistake 2: I had no idea soldering irons could leak electricity into devices. I need to now check the driver's current sense resistor when powered, to measure voltage drop. It's possible I damaged the driver with ESD but I'm inclined to guess that I damaged the more fragile diode. And hey, if I damaged the diode, it's actually cheaper than the driver. I'm kind of upset over my carelessness and I'm putting this project away for a while. I'll post an update if I can learn anything useful with my multimeter in a week or so. Thanks for the assistance, I do appreciate it.

 

[Pastor of Muppets]

Okay here is a resolution that I eventually came to. I bought a multimeter but couldn't find the current sense resistor. Claude AI told me that I can measure the output voltage of the driver at the diode legs. It told me that if the driver is outputting the maximum voltage (approx 15 volts in this case) instead of the voltage it was set for the diode (6-7 volts in this case) then the diode is shot. The meter clocked the output at 14.23 volts. So I imagine the diode is toast. Thanks for everyone's help, and now I know that I need to heat up my soldering iron, unplug it from the wall, and then solder the battery board to driver. My soldering iron has one of those 3/8 phono type grounding thingies that you alligator clip to your metal worktop but I'm not trusting that with a $78 device. An expensive lesson, but maybe this thread will help someone in the future. I can buy a new diode for $23 and I'll probably buy two in case I kill the first one with too much soldering heat. I'm just assuming the driver is fine because they're a bit more robust than diodes, especially the finicky 405nm single mode diodes.
Cheers.

Edit: I remembered the AI troubleshooting results incorrectly and had written above that the *driver* was toast if the voltage at the diode end was at maximum.

Edit part two: Good News

Once I decided the diode was fried I chose to use it to practice soldering. Now, the only thing I changed when I soldered this the second time (it worked the first time when I tested it on bench) was I slightly bent the unused 3rd diode leg (which would be where the photodiode connected in certain industrial applications, but is not used for laser pointers) away from the driver board so it wouldn't short against anything. Well, I was going to practice desoldering this diode and I looked at it with a macro lens. I noticed that I was a complete idiot (yeah I saw my IQ through the camera lens ) and it was a 2 legged diode with a cold solder joint on the negative diode leg. Which was the leg I moved away from the PCB, assuming that it was the photodiode leg, because it was unsoldered. So I heated up my soldering iron, unplugged it, resoldered the negative diode leg and connected it to the driver. It worked. Now I probably semi-fried the driver by powering it with no load connected, but I was able to solder up the battery board and have a functional laser. It seems to have been a cold solder joint from the reseller (DTR Lasers). So, for a note to any other n00bs, check all your solder joints.

Gotta love a happy ending. But mostly I'm happy that I didn't break my project. It was so deflating to believe that I ruined my first project. Now I can put my laser safety goggles on and do some practice drawing on the epoxy squares that I've filled with strontium aluminate GitD powder (yes, I'm easily amused)