My laser does not produce light.. My Laser does not "fire". What is wrong? How do I fix the laser to make it fire?

Quick Answer:

See if you forgot something normal. Is the chiller on? Is the main door closed? Is the Laser enable button engaged? Is the chiller alarming? Is the water clogged? Is the laser power setting high enough (laser power/corner power)? Is the mirror alignment right? Is the focal lens dirty or blocked?

Complete Answer:

Checking for why my laser does not produce a laser at the target material. Sudden results and was not expected.

1) See if the laser tube produces light inside the glass.
a) Even at 50% or more power, the laser tube only produces a small flare at one end of the laser tube or just sparks. The CO2 gas has leaked out of the laser tube. Check for any small cracks in the laser tube. ...possible burns through glass ...burn through epoxy...
b) Some laser light is produced inside the laser tube, but light does not get outside the laser tube. The output coupler lens is damaged.
c) A complete column of light is seen going from one end of the glass to the other end, but the light does not reach the focal lens. You would need to go through the laser alignment procedure. Alignment has been knocked out..
d) The Laser light is wrong color. The laser tube is deminished capability or the power supply is damaged.

2) The laser machine has been moved or the chiller has been disconnected from the laser machine. Make sure the coolant hoses are connected in the correct direction. From chiller "Outlet" goes to the Laser machine "inlet". check for direction of coolant flow.

3) Check the flow sensor .. not damaged... not clogged by mold or dirt. The coolant (water) must be flowing on the correct direction for the flow sensor to work right. You can look at the laser tube to see the water and bubbles flow direction toward the laser-light output end of the laser tube.

4) Look at the laser tube.
a) Make sure that the glass is not broken.
b) Make sure the laser tube is not FULL of water.
c) Make sure the wire connections are secure.. Do NOT break the glass nipple at the connection area.
d) Make sure the water flowing from inlet toward the laser ouput lens.

5) Check the chiller interlock cable. The cable needs to be connected securely.. snug. If the cable is removed, the laser will not work. The chiller must be running and shown in a normal-safe condition.

6) Check the main door sensors. Look for if the sensor is damaged. It is possible that a sensor wire fell out of place and was snagged, torn, or otherwise or damaged by moving parts of the laser machine.

7) Make sure the main door is closed. The laser machine has safety system to not allow the laser to "fire" if not safe situation.

8) Check the entire electrical safety system by bypassing the WP and G. Place a wire jumper from WP to G terminals. The 6-pin connector should be labeled as H-L-WP-G-IN-5V

9) Check the analog voltage input of the "IN" terminal. Use a volt meter with settings for DC voltage, and appropriate range for readings near 5VDC. The black wire should be connected to the "GND" terminal of the (6-pin connector) power supply. Connect the red wire to the "IN" terminal of the (6-pin connector) power supply. This test should reveal an analog voltage appropriate to the laser power setting. A voltage of Zero will not allow the laser to "fire".
***A setting of 40% power will give (40% of 5 VDC)=2VDC. A power setting of 75% will give (75% of 5VDC)=3.75VDC
***Note: The laser controller will only send this voltage to the laser power supply during a running program.

10) Run a test program that can fire the laser for enough time for you to test the voltage at the power supply. Check the voltage going into the "L" terminal. Use a volt meter with settings for voltage, and appropriate range for readings near 5VDC. Connect the black wire to the "G" terminal of the (6-pin connector) power supply. This voltage should change from high to low. While laser is told to "rest", the voltage should be near 5 VDC. When the laser is told to "fire", the voltage should be near zero.

11) Check the voltage coming into the laser machine. The voltage should be either 220 or 110 .. depending on the laser machine design. If the voltage is too low, then the laser power supply will not work right. If your laser machine needs 220VAC, but is only getting half that, then one phase of the incoming electric could be damaged.

12) Check the entire "Fire" command. Use a short section of wire to bypass the trigger command wire by connecting the G to the L terminals. Run the testing program to see if the laser works.

If these diagnostic steps have not led you to a repaired laser machine... You may need to call for a technician to come to your business and fix your laser machine.

FAQ item was submitted: 10/10/2012 By: Raymond L. Scott

Contact: Raymond L. Scott ... Owner Engineer,, (513) 217-5707

Related Topics: laser not fire, no laser output, power failed