Laser current slowly dropping while cutting


I own an china 100w laser which is now 3 years old. While cutting wood (22mA) after some minutes the current drops to 21mA then 20mA and so on. Is this an issue of my cheap power supply (VEVOR) or is this caused by the tube slowly coming to its end? The original MYJG-100 died which symptoms where that the laser had non-permanent cutting and bad engraving.

If so which power supply / tube would you recommend that is at least shippable from an eu warehouse?

Thank you!

I had dropping current when my PSU went bad, haven’t lost the tube yet, knock on wood.

For my first choice, I’d get an SPT tube, they have a reputation for being better than advertised. For me specifically, I’d get the TR series with the integrated red dot. I use GaAs lens’ from time to time, so they would block it, but I’d still go for the SPT TR.

Check your PSU voltages against the tube requirements. A good PSU will often supply an SPT tube one step higher than the label rating the SPT tubes are that good.

Second question, have you run an actual power test on the laser output to see what mA you hit your 100W at? To see what your power curve actually looks like? My factory tube is pretty bad, takes several mA change at the top end to get even half a watt more.