If the laser tube fires a laser when the test button is pressed and the ammeter reads about 8 mA, the laser tube is normal, and you need to check the laser control signal of the main board as follows:

1. Draw a circle with a diameter of 50mm in the software.
2. Set the power to 50% and the speed to 1.
3. Move the laser head to the leftmost side through the software.
4. Use the dip switch on the upper left corner of the engraver to enable the rotary axis.
5. Initiate the engraving from the software and check the LCD of the power supply.

If the “Laser signal” always reads “off” on the LCD, measure the voltage between L and GND on the laser power supply (as shown). Normally, the reading is 0V when the engraver is processing and 5V on standby.

• If the voltage reads normal, but the laser signal remains “off”, replace the laser power supply with a new, identical one.
• If the voltage always reads 5V, replace the main board with a new, identical one.

If the “Laser signal” reads “on” on the LCD, but the current remains lower than 4 mA.

1. Check whether the ammeter has been adjusted to the maximum. If not, make it so.
2. Set your multimeter’s beeper on.
3. Check the continuity between the L-AN of the CN5 terminal on the mainboard and the laser power supply IN (as shown).

• If the line proves conductive, then measure the voltage between L-AN and GND of the mainboard, IN and GND of the power supply (normal reading being 2.5V of both). (as shown)

• If the voltage reads normally and the laser tube still won’t fire, replace the laser power supply with a new, identical one. If the voltage reads abnormally, replace the mainboard with a new identical one.