3/15/18 Laser Cutter PSU Diagnosis


Date/Time: 3/15/18 9:00 ~ midnight

Equipment: Thunderlaser Laser Cutter


  • Thomas Orr, Mo Haroun (initial diagnosis)
  • Jake Lee (second independant diagnosis and writeup)

Images album: https://imgur.com/a/VkVdq

Relevant Terms

  • Right panel
    • Contains various control boards and power supplies
  • Back bottom panel
    • Contains various power-related connections, including breakers
  • Back top panel
    • Contains the glass laser tube
  • Left panel
    • Contains the power supply for the laser
    • Difficult to access


  • Laser not firing - head traces the design but no cutting
  • Red targeting laser does fire - cutting laser does not fire

Safety Warnings

  • :warning: Heavy equipment movement
    • Do not move the equipment without intimate knowledge of cable, air, and water connections behind the machine
    • Two people minimum recommended to watch cables and connections
    • Double-check after diagnosis that all connections remain connected (electrical, air, water)
    • Move cables out of the way to avoid pinching with wheel
  • :warning: High voltage - requires machine to be on during diagnosis
    • Only visual check of connections and breakers while the machine is on
    • Wait ~10 mins after turning off machine to release possible capacitive charge before physical inspection
    • Do not disassemble anything with a "seal" sticker on it (will void warranty)
  • :warning: Security
    • Always lock panels after diagnosis to avoid tampering or accidental disconnections
    • Keys are low quality and may bend, do not force. One key is destroyed already
  • :warning: Glass
    • Laser tube is made of glass, do not touch
    • Also, very expensive


  1. Have on-hand the following
    1. Camera
    2. Flashlight
    3. Lasercutter keys
      1. :warning: Security
  2. A guide was provided by the manufacturer: http://jakehlee.com/assets/doc/laser_diagnosis.pdf
    1. The PSU pictured is in the left panel.
  3. Move the equipment as shown in Figure 1.
    1. :warning: Heavy equipment movement
    2. ULS+BOFA first, Computer+BOFA second, Thunderlaser third.
    3. You should be able to comfortably access the left, rear, and right of the Thunderlaser.
    4. Disconnect electrical cables as necessary. Avoid disconnecting air lines. Do not disconnect water lines (you shouldn't need to)
    5. Do not pinch cables with the wheels on the equipment. Have a second person watching for cables.
  4. Turn on the laser cutter and perform a visual check of the right panel and rear panel boards, power supplies, and breakers.
    1. :warning: High voltage, Security
    2. On the right panel, the control boards should have some lights flashing, and the two PSUs should each have a green LED on.
    3. On the rear panel, no breakers should be tripped, and some terminals should have LEDs on.
    4. This step requires familiarity with general electrical systems.
  5. Look at the PSU within the left panel.
    1. :warning: High voltage, Security
    2. Findings
      1. No LED was on in the PSU. The provided guide indicates that an LED should be on. See Figure 2.
      2. The fan was not spinning in the PSU. The blades of the fan were visible and not spinning. See Figure 3.
      3. The model of the PSU is HY-DY20. See Figure 4.
        1. Shandong Jinan Hongyuan Electronic Co. 130W-150W RECI CO2 Laser Tube Power Supply
        2. One year warranty
        3. http://www.jnhyec.com/en/productxx.asp?signid=122&proid=188
      4. There is an additional control board next to the PSU, not sure if relevant. See Figure 5.
      5. I also followed most cables to their respective terminals and connections and found no abnormalities.
      6. I did not take any electrical measurements due to lack of information.
  6. Diagnosis: Broken PSU.
  7. If continuing with the rest of the steps in the PDF
    1. :warning: High voltage, Security, Glass

Solution Options

  1. Directly purchase a HY-DY20 and replace.
    1. $280 on Amazon
    2. Shipping by March 21-26
    3. https://www.amazon.com/Reci-Power-Supply-DY20-Laser/dp/B01MQZSXGB
    4. May void warranty?
  2. Receive a replacement PSU from Thunderlaser.
    1. Free, still within warranty period
    2. Potentially take longer to ship (or not, they have been pretty quick in the past)
    3. Won't void warranty


PSU replacement did not solve issue, different issue diagnosed by Thomas Orr. Writeup coming soon.


Figure 1

Figure 2

Figure 3

Figure 4

Figure 5