Trouble Shooting a 445nm Doide and Driver

I would be thankful for some insight on my laser. It's a 445nm diode from a casio 2500 lumen projector. The driver I run pumps 1.82A and has its own aluminum heat sink soldered onto it.

My first build, link in my signature, just randomly stopped working today. It was functioning fine, and two hours later I went to turn it on again and nothing happened. I tested the batteries and the switch with my DMM and they are both fine. I pulled the heatsink out of the laser and when I turn it on the driver doesn't even get warm. I've left the diode in the heatsink for the moment.

There are no signs at all of loose or burnt connections and everything appears the same as the day I put it together. Where I'm stick is how I should go about trouble shooting the driver and diode. I have a DMM and have a good understanding of circuits, any recommendations?

Thanks.

Just a note the lumen of the projector does not identify which diode it is. The series usually will however as in A series/M series/H series.

Is the driver a linear or buck driver?

What driver is it? I assume it is not a boost or dual boost driver set up as you said batteries.

What kind of batteries are they? Protected or non protected? It is possible if they are cheap and protected it may be tripping the protection under load.

If you have ruled out the batteries I would usually start by taking parts of the host or the whole thing out of the equasion.

First you can try bypassing the tailcap by removing it with the batteries in and using a peice of metal or wire to complte the circuit betwen the battery and the host to rule out a faulty tailcap.

If that does not work move on and try connecting the driver directly to your batteries instead of using the connections in the host. This can be easier with a power supply but you may not have one.

If still no joy you would need to break it down completely and start by testing the driver on a test load. If it shows good you are pretty much left with it the diode that is bad. If you had a variable power supply or another good driver you could test it.

DTR said:

If that does not work move on and try connecting the driver directly to your batteries instead of using the connections in the host.

Click to expand...

Thank you, this solved it. The aluminum ring holding the driver must have moved enough to lose connection which I didn't think was possible but I reset it and it works now. And thanks for the tips, next time something breaks I'll know how to address it.

Appreciate your help.

:beer:

You da man DTR, I would rep you more but it told me to spread the love elsewhere...