Quoted from RCA1:Hopefully someone can assist with troubleshooting.
OP asked for "someone to come and try to repair" but if pressing the Replay button doesn't activate the Coin relay,
Inspect and diagnose this circuit with Alligator clip jumper wires
https://pinside.com/pinball/forum/topic/gottlieb-big-shot-repair#post-6305153
http://www.planetimming.com/Pinball/troubleshooting/EM%20Troubleshooting.pdf
http://www.pinrepair.com/em/index3.htm#features
Example of a pinsider actually doing this https://pinside.com/pinball/forum/topic/red-baron-tech-question#post-5858156