PrevalSprayer (PVE268) Preval Power Unit

I had to give up on the job I was doing because the Preval sprayer was temperamental. It works well when it works but it doesn't always work. I watched a video of how to use the Preval sprayer. I went through 6 trying to do one job. The last one was brand new and didn't work no matter what I did. It was a waste of time and money for me.