If a Pro-150 gives the Pt [pot top] fault code, or just gives a continuous rapid beeps, this indicates a pot or wiring fault or blown F1 fuse track such that the voltage on the top of the pot
is high (above 4.7v) or low (below 2.5v).
It could also be a low (less than about 1K) or high (greater than about 19K) resistance pot, or a broken wire or connection (either end of the pot) or a short to the pot. The controller will behave as if the throttle is at zero while the fault persists.
There is also a very thin track on the PCB adjacent to the 3 and 6 way connectors, it’s circled in red in the picture below… This is actually a scratch through link that allows modifications to the input circuit but under certain short circuit conditions we have seen this act as a 3rd fuse track and blow. If this does happen to your controller then just bridge the pads with some 1A fuse wire.