Hi, I purchased a PowerPlasma50 and have recently ran into a problem with it. After preforming a cut the airflow no longer shuts off. The post flow is set to 10 seconds and was functioning correctly up until yesterday. On occasion the air flow does stop. If the airflow is constantly blowing out I have to turn off the machine and then turn it back on before I can preform another cut. Is this a problem with the spring in the solenoid? Can I just re-tension the spring?