Laser not firing with test button

I have a 100W Redsail Laser and the laser stopped working.

I have 220V to the laser power supply but the laser does not fire when the test button is pushed. Does the test button need water flowing to work? I have water flowing through the tube but I don't know how the system senses water flow. Can someone explain that to me?

Assuming the water flow is sensed correctly does that mean I have a bad power supply? Is there a visual indicator of the power supply working? I know some have a light when the power supply is active.

If the power supply is bad where can I find a replacement? I see many 100W/110V but no 100W/220V.

Any help would be greatly appreciated.

Tom