Missile Command P1 + P2 Start Problems

[roberthazelby]

Morning all,

 

I am currently experiencing a slight niggle with my Missile Command cocktail. Over the past couple of months my P1 and P2 start buttons have become less and less responsive, up to the present date where they no longer respond at all.

 

Initially the buttons would become responsive after the machine had been on for 5 or so minutes, but now even that doesn't seem to make them work.

 

The connections from the buttons to the PCB seem fine. Is this a documented problem? If so, can anyone suggest a location or locations on the board I should start to investigate?

 

Many thanks,

 

Robert Hazelby

[Arcadenut]

quote:

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Originally posted by Robert Hazelby:

Morning all,

 

I am currently experiencing a slight niggle with my Missile Command cocktail. Over the past couple of months my P1 and P2 start buttons have become less and less responsive, up to the present date where they no longer respond at all.

 

Initially the buttons would become responsive after the machine had been on for 5 or so minutes, but now even that doesn't seem to make them work.

 

The connections from the buttons to the PCB seem fine. Is this a documented problem? If so, can anyone suggest a location or locations on the board I should start to investigate?

 

Many thanks,

 

Robert Hazelby

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First thing you should do is determine if its the Buttons, the wiring or the board. If its the buttons or wiring its easy to fix. If its the board, you'll have more work to do.

 

To check the buttons, take a wire and short the two sides of the button.

 

If you look at the bottom of the button you should see two wires going to it. 1 wire is ground, the other wire is the credit trigger.

 

If you short these two together, you should get a credit. If you can do that reliably and the button itself doesn't then you need to do 1 of 2 things.

 

1) Clean the button. If its a leaf switch then use Rubbing Alcohol and a Q-tip and clean the two little metal dics at the ends of the leafs.

 

If the switches are Micro-Switches, then you wont be able to clean those and you'll want to choose option #2

 

2) Get new buttons.

 

If those don't work, then you can check the wiring and the edge connector to make sure they are good. Look for nicks in the wires, bad connections on any Molex Connectors (White blocks that connect runs of wires), or the Edge connector may need adjustment.

 

If all of that is good and it still is acting up, then you have a board problem and you need to get that fixed.