Any chance at all that when the head went up you pinched a connectior and it worked fine but after many hours being pinched the wires were stressed and broke ??
See this in a Bally Corvette
Guy bought it set it up - worked flawless
Then the engine assembly failed …
He took the entire game apart to find the flaw
I went throughout the entire game to fine a ribbon cable crushed … and guess what it controlled
Sorry this happened on a new game