Sounds like a dirty or misgapped switch in the score motor or relay. I dont know the schematics of that game but that's where I would start. Make sure the switches are gapped properly and when the close they make a good connection.

does that particular score reel move ok during gameplay ?

I would suspect ONE of the many leaf switches on the "reset relays" is either dirty or out of alignment or the "switch stack" needs to be tightened

http://www.pinrepair.com/em/index2.htm#clean
I don't use a file myself anymore simply a piece of plain paper might do the trick but I use the "magic brush" method now.

video of demonstration from this link:
https://pinside.com/pinball/forum/topic/nics-american-pinball-tour-aka-im-coming-to-fix-your-games/page/47#post-5120291

Hi Chuck, Welcome to pinside!

Which score wheel and which player?

If that score reel moves OK during gameplay, Inspect and diagnose this circuit with Alligator clip jumper wires
http://www.planetimming.com/Pinball/troubleshooting/EM%20Troubleshooting.pdf
http://www.pinrepair.com/em/index3.htm#features

pasted_image (resized).png

So it doesn't move at start but works fine during the game? Does sound like the motor in the bottom of the cab. Dont know what it's called. My mars trek did that when I got it. Guess I was lucky, I just had to clean the stacks and regap them. Been working since.

I think he means it doesn't move to reset to zero.

the "#1 reset relay"(in the head) the white-wire-w/black tracer contacts are probably dirty or mis-adjusted

during startup the reset relays will be the ones clacking back & forth in the head while game is trying to reset ... if the reel kinda moves turn all the lights off it'll be the one throwing all the sparks

Capt Fantastic color chart (resized).jpg

see post #3, clean the contacts , tighten the switch stacks, adjust the blades if need be. the video if you can access it is terrific: https://www.facebook.com/nicholas.schell/videos/10156172583066806/