The ion source’s HV connector has a loose connection.
Easy Spray Ion Spray Source Models:
If you have a digital multimeter that can measure 20 M (mega ohms), do the following:
1. Test the meter’s batteries, and then set the meter to the appropriate resistance setting or range.
2. Measure the resistance from the HV pin on the back of the ion source to the spring-loaded bolt located inside the housing. A functional HV connection has a measured resistance of 18–22.