We have a syncwave 200 and two weeks ago had a "POL ERR" message come up. We switched the polarity back and forth and could not get the message to go off. After about 1/2 hour of scratching our heads the message disapeared and we used the welder for two hours with no issues. This weekend we had the same issue however the message never went away and we could not use the welder. Any ideas? Very disapointed since we do not use the welder much.