Any YAG laser experts here ?

[BillTodd]

I've just been given a pro laser engraver. Its a bit of a monster (150W  @ 1084nm  2.2kW psu with cooler) and broken so I'll probably break it, but I thought I d ask if anyone has  YAG laser experience.

The machine was scrapped with a 'diode low power' fault. I'm guessing this means the 808nm pumping diode has dimmed.

So, how easy would this be to replace the pump

[tom osselton]

There are tons of diode laser heads on Amazon I’d check them out.

[BillTodd]

Under the lid ..

Playing with the software, I noticed a setting to extend pump diode warning time , so I am crossing my fingers that there are a few blasts left in this thing .

[BillTodd]

Well , the extend warning is only a software thing. The diode pump isn't working :-(

I opened the diode pump box and investigated:
The pump consists of 6  laser diode banks each with 25  chips .  Driving it with a constant current supply I can see a good few chips not working .

The voltage across the array was only 9V or so at 2A - given this is driven by a 50A 45V supply , I can see the need for water cooling.

[BillTodd]

BTW these diodes shine down on to the YAG (yttrium aluminium garnet) crystal which is encased in a water jacket for cooling. The red laser light pumps up the electrons in the crystal . When the electrons collapse to their rest state (controlled by a Q switch) they release Infrared photons , which burn the crap out of what ever gets in their way.