Remove the power cover of the engraver (see video).

Measure the voltage of the exhaust fan’s plug (as shown).

• If the plug voltage reads 12V, replace the exhaust fan with a new identical one.
• If the plug voltage reads 0, check the continuity of the wiring from the laser power supply to the exhaust fan.

Set your multimeter’s beeper on.

Check the continuity between the 12V output of the relay to the fan's plug (as shown).

Check the location of wiring disconnections and repair them.