Needing help to find a schematic

Thread Starter


Joined Jun 23, 2020
I am trying to find a schematic for a CO2 laser machine power supply. Here is a pasted web address for the power supply. The model is a YL-U1 28mA max current, 35kV output voltage. I was given four of these, one of which you could see the problem real easy. Two of the high voltage switching transistors blew up and one 1W resistor had opened up. I have replaced these parts and the fuse the power supply does power up. There is a test button on the supply when I push it I can hear the something on the high voltage fly back wire that goes to the laser tube. The other units do not have anything obvious. These units are used almost 24/7 so wondering if the fly back transformers could be the week spot. Thanks for all your help.


Joined Jan 23, 2018
First question is how will you know if the supply is working? 35,000 volts is nothing to play with. If you can trace out the circuit and post it we can help. Finding circuit information usually means using a search program and the model number. Then you get 1200 hits wanting to sell you one, when they have no clue what it is. and there may be one hit that has the circuit drawing. That is the one you need to save.