Hello, I have faulty EWM Stick 200H welding with circuit board TRSQW3. Maybe someone have any clue, what does LED "POLA" mean? On board besides this one, there is also "EL.", "STRSTP", "+15V, "-15", "+5V", but I guess the are not so important. I just want to understand what direction to dig. This board seems is not very popular and not much documentation.
-Peter