Sure sounds like a pressure switch. I had something very similar with my furnace.
You need to determine the logic of the startup cycle and troubleshoot each component in order.
You can determine if the pressure switch is working by checking with an ohm meter.
My guess is that when the power vent kicks on, the pressure switch should close, and then gas valve open, and gas flows. Then a flame sensor would check to see if the unit lights within a few seconds, and if not, it will shut down and try to recycle.
If the pressure switch closes when the power vent kicks on, and the gas valve doesn't open, you've got a different problem.
Unfortunately, testing the control panel is difficult, if not impossible, other than swapping one out.