To ensure that there is no problem with the power supply, try to start the arc by friction first. If the friction can't start the arc, it means that the main circuit of the welding machine is broken. Check the input terminal, rectifier bridge and inverter module. If the arc can be started by friction, it shows that the main circuit of welding is good. This is a problem with the high frequency circuit. Check the high frequency coil. Having said that, I like it.