Hi, I have 1250 mounted on CNC machine, it works for about 1,5 year ok but now I have problems with kerf angle, arc is unstable, sometimes it is on left side, sometimes on right side, angle can be 7-8 degrees. It is not always, I cut 6mm steel plate with 50Amps and fine cut nozzle, speed is 20mm/m, air is dry and clean, consumables are new. I changed machine torch but the problem is still there. Grounding clamp is on material with clean contact. In device is small pcb on front plate, there is some leds, when it cuts all green is illuminated with two red leds - start and afr, is this normal?