It seems like you really need to try another PGM-III. Or send your PGM-III to someone else to try?
But, as that is difficult to do, maybe just to make absolutely sure its not the battery, try hooking up a well charged car battery via jumper leads, and try running it.
I have been made to look pretty stupid, due to what I thought was a good battery, in the past.

With race day looming, maybe you can just set the power valves permanently open (with the servo wires disconnected) and see if it will be OK at the track like that?
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[color=#808080][size=9]Yes,.. I too know how to waste Time and Money,...