You soldered it up wrong. Solder and test before reattaching the hulls next time. It can be frustrating when you're tired so if you haven't fixed it yet, take the night off before you become a member of the "blown boards club". I'm the President btw!

As for throwing tracks, was it because of the damaged pin? In 3 years I've never tossed a track on a Pershing. If your idler broke then your tank is SOL. Did you mean the return rollers came apart? That is more common problem, the solution is to pop them all off and reglue with CA. I use 3 drops so I can still pry them apart if need be.