Unlike the PowerCab, the PowerPro system was designed before sound decoders became common. Sound decoder consumed a lot more current doing nothing than non sound decoders. This included some high inrush current issues that can make the sound decoder look like a short circuit when non in fact exist.
It should be noted that you can BUY a programming track booster for the PowerPro that will give you the best possible performance. These programming track were developed BECUASE of the Sound Decoder power support problem experienced by both PowerPro user and other DCC systems. I recommend one get the SoundTraxx PTB-100 board. For more information go here:
This section goes through the steps to modify the PowerPro Programming Track to give you the best possible performance.