Help ........ new laser tube and PSU

New to co2 laser engraving and maybe this is the wrong forum but I’ll ask anyway.
I was given a Chinese 50w blue white laser system minus the laser tube. Installed new tube and was able to engrave but the laser never turned off and fire during traversal moves. Research says the PSU was too weak. Replaced the PSU and laser will test fire but won’t when I attempt to run a cut file. Any help appreciated

Hi Ed
I had a similar problem on a laser I was working on for a friend. I found that they had accidently switched some wiring on the PSU and had inverted the TL connection with the IN connection. It may be worth a try.