first two wires are red(+5vdc) next is green (ground). Its close quarters to check the voltages at the power supply itself, I usually test them at CN-1, its the big plug on the right side rear of board. The white switch, left hand side lower front, the plunger can be pulled out, that would tell the machine that the front door is closed,(even though its not) then you could try the reset. the two switches below the bill acceptor, one is for getting into the test mode, the other is a reset.(bottom one) same as using the key switch. you can jumper across them if you want, or replace with a open momentary push button switch.

I do not have keys available, or power supplies. To determine which machine you have SG-50 21 1/4 wide, SG-32 18 3/4 wide.