The easiest way to figure out if your laser source needs to be replaced is to try some sample cutting. In the cutting mode, the laser is going to be at maximum output. The manufacturer of the system has some recommended power settings for certain materials – start with those settings. If you have to slow the speed down to cut through the material from the manufacturer’s settings, then I would say your laser source is weak. It’s pretty simple to check or you can use a power meter.
Keep reading about used laser sources.