Did I kill my PHR-803T diode?

I'm on my first build and think I might have killed my ONLY laser diode. AARGH. But before I jump to conclusions I was hoping for a few experienced opinions?

I'm a technician by trade so am used to working with sensitive electronics though not very knowledgeable and have no formal training. I'm driving the diode with the rkcstr using 9v battery for testing purposes. I set the pot on the driver to the lowest setting (measured ~50mA on DMM) & connected a LED as a test load and it lit up beautifully, so I proceeded to solder on the LD. I DID NOT read the driver manual before doing any of this. BRILLIANT! So, I didn't know I should have shorted the LD outputs to drain the capacitor before soldering the LD. If that didn't kill it then it probably burned to death while I struggled to desolder the little circuitboard that came attached to the diode.

I never once saw the tiniest bit of light from this diode, not even a flicker as it died. :angel:

So is it most likely dead or is it just not reaching its threshhold current, or could there be another problem?

Even before threshold you'd see some light. A blackout like this is not a common failure mode. Check the current again.

Cyparagon said:

Even before threshold you'd see some light. A blackout like this is not a common failure mode. Check the current again.

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Really? Even if I baked it with the soldering iron?

Cyparagon said:

Even before threshold you'd see some light. A blackout like this is not a common failure mode. Check the current again.

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THANK you, I am now getting a small amount of light out of the diode. I seem to be hitting the threshold RIGHT BEFORE the pot maxes out. Unfortunately I can't measure the current since I blew out the fuse on my DMM. It looks like I won't be able to get enough power from a 9v battery to drive this thing, does that sound right? There's a considerable amount of heat, both from the diode and the driver, even after just a few seconds of operation.

the 9v cannot provide enough current!

Invest in some 18650s. They kick.

Thanks guys, the 9v was just for testing purposes until I devise a decent power source.

Thanks for the help everybody, greatly appreciated! :wave:

Coherent Light said:

the 9v cannot provide enough current!

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Sure it can. The PHR only needs 100mA or less. Battery life won't be impressive, but it certainly works for testing purposes.

Cyparagon said:

Sure it can. The PHR only needs 100mA or less. Battery life won't be impressive, but it certainly works for testing purposes.

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Was just about to say that.

I have a 9v batt in my PHR driving a DDL , works fine.

I made a 7mW 635 off a 9V and it lasted a good 20min or so

Cyparagon said:

Sure it can. The PHR only needs 100mA or less. Battery life won't be impressive, but it certainly works for testing purposes.

Click to expand...

ped said:

Was just about to say that.

I have a 9v batt in my PHR driving a DDL , works fine.

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So does that mean there's something wrong with my diode, or is it the rkcstr driver that's the issue? I literally had the pot cranked almost to the very top before I saw any light... the diode turned on like a light bulb at that point but wouldn't go any brighter since I was at the driver limit. The driver felt like it was about to catch fire after only a few seconds & the diode was putting out some good heat too. Then the diode went out so I removed the battery to test it with the DMM which measured under 9v. I had been using that battery to test the driver's output with the DMM and LEDs earlier that day, so maybe the battery is done.

:thinking: