We have what's claimed to be a "50W" Chinese laser, roughly 6 months old. I'm under the impression these are actually 40W tubes that test better than 40W.
A couple of months ago the power supply failed, dead stop. Since the outfit I bought the laser from is an importer only, I bought a replacement power supply from an eBay supplier in China.
Ever since I replaced the power supply, the machine tends to break out into a fairly loud squeal when cutting. When it does, the apparent power drops off, because it often won't cut completely through the 1/8" clear cast acrylic we usually cut with it. During the odd times that it doesn't squeal, we seem to be getting normal power from the power supply and tube.
Any ideas what might be causing the squeal? My *guess* is that something in the power supply is oscillating, or finding some kind of unwanted resonance. I've considered trying a different style of 50W power supply, but don't want to just start throwing money at it without at least some idea it could be successful.
Thanks,
--jim