anyone knows what happened?

[svdr]

Ok, so I got this PL450Bdiode from DTR. Copper module and a 100mA linear Moh's driver. Assembled al the stuff in a 501B Host with appropriate heatsink. The laser worked fine for several months. Then, a couple of weeks ago, it just faded out over a couple of seconds. It never has been on for more than a few seconds at a time. Thought the batteries were empty, but the laser didn't come back with a new set of batt's (Energizer Lithium 1634). When I tested the used batteries, they were like new, hardly used.

I already opened the assembly, found no twisted or loose wires, all seems OK. The driver is a really simple board, when I metered the individual components, nothing seemed wrong.

It looks like something happened to the diode. Is there a way to see if it is still healthy?

 

[IsaacT]

1. The batteries you are using, what voltage are they rated for? And you are using two of them correct?
2. When you assembled the laser, what kinds of antistatic protection did you use? i.e.-floor mat, wriststrap, spray, etc.
3. Have you ever dropped the laser? If so, from what height, angle, and what did it fall on?
4. What temperature is the laser stored at?

These are the most pertinent diagnostic questions that came to mind. Others may have additional ones.

 

[svdr]

1. Standard Li-ion 3.3V, 2 of them indeed.
2. Wriststrap connected to ground, water tap. Don't know if this is important as it worked for months.
3. No.
4. Room temp.

 

[IsaacT]

Have you ever put the batteries in backwards on accident? Since the diode has stopped working and considering your answers to the questions above, my guess would be that you have experienced bad luck. Remember that while diodes are rated for around 5000 hours typically, running at different currents can affect lifespans and there can be units which do not live up to the rating.

 

[svdr]

Poor me, then...

 

[daguin]

First, clean ALL of the contact points

Second, test it by bypassing the switch
Just short the back of the battery against the case

Third, try a different set of batteries
Sometimes "new" ones are defective
Sometimes batteries will test like new, but not be able to give the current needed under load

If the above fails, disassemble and test the individual components

Peace,
dave