Please follow the steps below.

1. Turn the potentiometers on the ammeter to its maximum.
2. Press the test button on the ammeter.
3. Check the reading on the ammeter and the laser beam inside the laser tube.

• If the ammeter reads about 20 mA, nothing serious is going on with the engraver. You might need to check the lens, recalibrate the laser path, and adjust the focal length. 
• If the ammeter reads low, replace the laser tube or laser power supply.