The HV cabinet an overheat for a number of reasons.
The gasmix or the voltages can be off to the point where the HV chassis runs so hot that the cooling system can't handle it. It's pretty easy to check, just run it up to 100% and look at the ballast tubes on the HV chassis. If the core inside glows a little dull red that's OK, bright red is not good. There's a filament in the core that glows a white color, don't pay attention to that, look at the core that the filament is in. We don't want to see anything more than a noticeable dull red at the bottom of the core. If they're bright red after a few minutes at 100% the cabinet will never run cool.
Flow restriction/radiator- Just crimp the hose to the radiator in the HV cabinet, the pressure gauge on the chiller should go up a few psi. If the outlet hose from the radiator is warm, this could also be a flow restriction. If the hoses are cold but the radiator is hot, the internal dividers in the radiator are rotted or broke their welds. Remember to go to 100% power while evaluating the cooling system performance.
Fans- There's either a long axial fan or a newer 2 squirrel cage fan setup in the top of the back of the HV cabinet, make sure you have a nice strong breeze coming from these. There's also 3 fans in the bottom of the HV chassis, see if they're spinning, they always are! some correctly, some windmilling backwards. You need to stick a cable tie in the fan and make sure its running the right way and at a good speed.
An interesting thing here is it's a 3000 watt laser. Bystronic sold a 3500 watt version (3500 was a failure) that uses the same cooling system. Whatever is wrong should be pretty obvious.
Dirt and dead fans are the number 1 killer when it comes to the Bystronic HV cabinet.
Feel free to call if you need further assistance. 706-627-7854 I'm not giving away all my tricks here.
HenryRollins- Stay gold brother!
Chris Krug
Maximum Up-time, Minimum BS