Step Nine: Galaga Coin Slot repair
First if you take a coin and place it in the slot—Does it fall all the way through and not register credits? Or does it get stuck and doesn’t fall through?
A. If it falls through but doesn’t register a credit, then proceed to follow the steps below.
First, open the coin door. With the coin door open and the game still ON locate the two left and right switches at the bottom of the coin slot. With your eyes look at the wires coming from the coin switch. Make sure both are connected and soldered on. Not taped or glued etc, as some “home owners” have done which will certainly make it lose connectivity over time. If found, solder the wires back in place. One to Normally Open the other to Neutral.
Second, If all wires look good with the tip of you finger trip (push down—as if a coin was falling through it) the switch and see if you can simulate the Quarter pushing down the lever. If the credit registers when you push it down but not when a quarter goes through, simply adjust the strike path of the quarter by bending and shaping the lever so that the quarter will trip it.
Third, If your finger can’t register a credit manually, then replace the switch itself with a new coin slot switch and solder the wires from the old one onto the new switch. The switch has two screws holding it in place. Unscrew these and the switch simply can be removed. Un solder the wires but make a note of the orientation before you disconnect them. Once your new switch arrives then solder the wires on and screw it back into the coin slot.
B. If your coin gets stuck and doesn’t fall through. Open the coin door and watch the path the quarter takes. Chances are if you watch where the quarter is getting stuck you will find that a paper clip, paper, junk, or Canadian quarter is blocking the path. Simply un block the path of the quarter. You may want to open the coin acceptor like so in order to further remove any obstical in its path. You may just want to replace the coin acceptor at this time with a new one.
I recommend these. The Quarters never get stuck!!!
What voltage is the for the coin slot.
If you are wiring the coin slot you would take the Coin 1 wire from the harness connector which attaches to the PCB board then run that to the coin slot switch at the bottom of the coin mech. look at the pinout on the pinout page of this site and find the coin 1 . this wire would attach to the bottom of the coin slot switch. then a ground would go on the COM (Common or stands for ground) port and the Coin 1 wire goes to the NO (Normally open) port (The other should say normally closed no used) please look at the coin slot post on this site for that info. It is probably +5 volts could be +12v but that really doesn’t matter. You can take a meter reader and see how much volt is on it. But the function of the slot is for Coin slot 1 wire to close whenever a coin goes through it by the weight of the coin fallen through the wire lever attched to the coin switch. So in other words when that coin switch is closed it registers a credit on the game. If nothing happen when you coin the game then look for a broken solder join on the Normally Open (NO) leg…. that means that if you tug gently on the wire it will probably fall off. take a soldering iron and solder it back in place. Also you should check the other wire on it as well( black wire should be a ground) If there are more wires on the coin slot the other two will go to the coin slot lights those should read +12 volts but they if not working should not effect the coin slot operation to start the game