Plasma Cutter Problem

[car man]

I have a plasma cutter that I bought new from " Northern Tool Cutting" ( plasma 375 ) which is not very old and just used a few times. It worked great , then gradually started getting harder to get the arc started , then eventually the arc went down to something hardly visible looking like an arc from a very dead car battery and only if you would drag the tip on the grounded metal. The machine turns on, the fan runs, and it has air pressure when you pull the trigger, but it just seems like there is no power to the torch. Is there a way to check if the problem is in the power getting through the torch or if the machine is not putting out the power to the torch? If I could figure out how to test the power out of the machine , that would narrow it down. What would the power reading be out of the machine and through the gun? Thanks in advance. car man