High Pitch noise from brand new PSU

[bratan]

I got new 60W PSU and 60W CO2 SP Tube from LO recently. Been running fine for about 2 weeks, now it's making this high pitched noise every 2nd run at which point cutting power drops (current is actually rising by 5mA). Sound seems to be coming from power supply. Any suggestions? Here's a video of this happening...
https://youtu.be/5bcMB4jTpQE

[Tech_Marco]

Check any arcing is happening.
It could happen inside of the LPSU. You can open the case and check. But, please do NOT touch or you may get electric shock! When putting back the cover, make sure you discharge it by fire up the laser tube for quick second

Marco

[bratan]

Thanks Marco!

I think I found issue. I had some car antifreeze in my water to fight bacteria growth. Issue seem to started to happen after I added antifreeze.
I just flushed tube with just distilled water and quickly tested, no more noise and power is back up. I'll run it without additives and see if issue comes back, if it does I'll check PSU for arcing.

[Tech_Marco]

Strange enough that it was caused by the coolant.
But I'll do some investigation on those antifreeze coolant. If it is really the cause, I think probably the resistance of antifreeze is much lower than water and causing 'bridging' somewhere

Marco