What is coil test mode?
My machine never says coin accepted as well as the two coils on the front door for the coin slot to operate successfully and let the quarter be allowed to fall into the hopper.
Super Continental 891-1
the game wizeguy posted the picture of in post #1 is probably a later E series machine that has computer boards in it, but he hasn't confirmed. Note the win meter is an led display ... but it's possible someone retrofitted that.
in any case, an electromechanical slot doesn't have any test modes.
if you're having problems with an 891-1 ... which is an EM slot ... best if you start a new topic so more people will take a look at it.