I have a 100 w laser I purchased off ebay that came from china-cnc-zone. I have had it a couple years and it has worked great. Untill Now.
The problem is that the power setting is changing while its cutting. It has a led display for the power and a series of buttons to change the settings, such as ( +10% , +1%, -10%, - 1% ) and so on.
If I start it at 15% it will cut for 5 to 10 minutes and then jump to 50 or 80. If I change it back it will eventually jump back up. So I've ruined a few projects.
Other then that it seams to be working ok . the power seams to correspond with what the power on the display says.