Here's a chart with the color codes that will help make this easier:
Now note the connector labeling for the credit switch: A4J3-2 and the number 13 on the box to the left:
That 13 is representing the color of the wire going to that pin. 1 = red, 3 = yellow. So you should have a red wire with yellow stripe going to connector J3 of the MPU board (A4), pin 2.
Look at the other side of the credit/reset switch--you'll see it goes to A4J3-14 and has the number 25 in a box. That means you should have a blue wire (2) with a white (5) stripe at pin 14 of connector J3 on the MPU(A4). Verify those wires are in their correct spots, as well as the 2 wires for the back inline target using the same method for determining wire colors.