Hello, I recently bought a power supply from aliexpress, a laser tube from aliexpres connected everything and started checking the operation with the test button from the control panel. So remove P+ and P- and put a small cable bridge between and test again.

If you power never goes above 3-4-5mA its your PSU, if you can see up to 18-22mA, its the tube.Īnother test to check, P+ and P-, if you have a flow meter on that one, when they go bad they can fluctuate a bit so it allows the tube to turn on-off-on-off-on-off very quick and it can cause this effect too. And keep one arm behind your back – just to be 100% safe you dont electrocute youself, your heart will stop – or at least make your hair look funny. But make sure you can do this without holding the probes, use clamps or tape to make sure you do not touch anything, and use a wood pen to push the test-button on the PSU.

You can do it from the negative cable coming from the tube, put the multimeter to measure resistance and one probe on the cable from the tube, and the other probe to the pin on the PSU where the cable were located. You can do it with a regular multimeter but you have to be very careful not touching any probes or metal when test-firing.

K40 lightburn