hello kevib71 & welcome to the site...
in regards to your Marquee light-up sign, make sure the starter is the correct size for the lamp you are using, dont assume that the one that was in there was correct, typically the starters have the lamp-wattage listed on themselves or their packaging (just for fun... a
Marquis is a nobleman, not a sign fixture,
) oh, & as an afterthought, it could also be a bad/open neutral wire, you may have 120 volts/hot to ground but that doesn't mean you have a return path for the power.
Also the lamp behind the coin entry bezel is usually for a "use correct change" function & will only light when the coinmech is out of sufficient change (nickels in the case of a Coinco S75-9800 A/B series)
to determine if your coinmech issue is indeed the coinmech or maybe the vend-solenoid, refer to the discussion on the Free-play switch under the coin mech section, it will show you how to test the solenoid using an insulated jumper wire between the coinmechs socket ( called the "Jones plug") pin no. 1 & 3
heres a link to a prior discussion on how the two bassic types of lamp circuits are wired...
http://soda-machines.com/discussions/index.php/topic,22575.0.html