Laser diode replacement

Has anyone here replaced their diodes on their lasers? Most replacement diodes I see look like the have a cap on them. The diode in my laser looks like an “open cap”. Can I use a diode with a cap on it?

In principle, you can use a protected diode. The diode only needs to have the same technical data as current consumption and voltage.

Thanks for answering, that is good news. I’m not sure why my last diode burned out, but what do you think about wiring an in-line meter in that measures wattage output?

complete waste of time.

The wattage output is not so interesting. it is interesting to know what current the diode is set to. Too high current is often the cause of an early failure of the laser diode. Look here from 6:30 ( .
I don’t know which diode you are using. The 4.5 W diodes (optical power), for example, should only be operated with a current of 3.0 … max. 3.2 A according to the data sheet. Most modules from china operate these diodes with 4 A.
In order not to reduce the lifetime, after burning, i let my diode cool down for a longer time (10 to 15 min.) before switching off the laser.

This is the laser I replaced my 20w laser master 2 with. Diode burned out less than a few hours later. When you say you let your laser cool for 10-15 mins before shutting off, do you mean that you let the fan run for 10-15 mins before shutting that down? Was wondering if I should of been doing that myself.

With my 20 watt laser that came on the laser master 2, I was running that 8 hours at a time all day, lasted almost 2 months like that lol

Yes, I let run the fan for 10 - 15 min. before shutting down.

If your laser does not have the protective cap then its junk.
Its a manufacturing defect and apparently there have been a lot of them coming out of China.
If they are made without the cap, they will simply not last very long.
There is a long discussion about this on F-book, “Norton’s den of lasers”.
Have a read.

Both the ‘20W’ that came with the Ortur and the ‘36W’ that came with the replacement are lying to you.

The most powerful diode on the planet is 7-8W. That’s from nichia in Japan.

Russian and Chinese diodes run around 4-5W, on their best day.

To make them ‘20W’, they use a technique called ‘pumping’, where they rapidly turn the voltage on and off, but a voltage much higher than the diode is rated for, which shortens it’s life by a ridiculous amount - they can blow in an hour or ten.

Add to this that the manufacturers use the most primitive electronics to drive the diode, with no protection from spikes or stray back-emf and it’s a recipe for high-cost/low reliability.

There are good manufacturers out there, but I’ve yet to find one from Asia or Russia that doesn’t lie through their teeth (and yes, Endurance are #1 at BS - charging hundreds of dollars for a 4W diode and marketing it as ‘20W’ - they say on their website “We use a high-quality NICHIA NUBM44/47 laser diodes with 7-8 watt CW power output.”, but still sell it as ‘20W’ - I bought one, it definitely didn’t have a Nichia NUBM44 or 47 in it - I know those diodes extremely well).

You can buy a genuine Nichia for around US$100-150, in a module, from a US supplier, with a surface-mount driver, with built in protection.

There’s really no need to buy Chinese diodes - they just aren’t any good.

And no, I’m not anti-Chinese - I lived there and other parts of Asia for decades and loved it. They make great stuff, but not online-sale diode lasers.

Ok, I’m on a replacement now from the 36 watt laser, I’ve seen the diodes you are speaking about for around 70-100$ on eBay, and about $130 in the housing.

Would it even be worth putting a better diode in it without upgrading the cooling?

I use


DTR sells mostly components, Barnett sells components and complete modules.

You will/should replace your driver, as well as the diode.

The heatsink you have is more than adequate.

Personally, I love the black buck 8A driver. It’s a proven design that can handle anything you can throw at it:

8A is its upper draw - you can’t draw more than the diode can take - its pull, not push. Voltage is what determines how much power you use and over-voltage is what kills diodes - it’s push, not pull.

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Thanks, those dtr diodes and housing look very convenient, nice board you posted too

You can buy just the board - you don’t need to get the prewired/heat sunk unit.

Search for BlackBuck 8A on eBay. A bunch of people make them. It’s open-source.

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