Button questions on S+ project

[Talarspeed]

      Take a look at the pictures of the deck buttons. In the first view you can see a spliced wire soldered to a terminal of some kind. (I had removed the spade connectors and microswitch at this point.)
 
https://imgur.com/M5jjVT9


 
This image shows it with connectors and microswitch in place.  There is a wire that runs from each button on the deck and soldered in place. I circled the taped/splicing.
Is this a ground?
 
https://imgur.com/l4xLJBr
 
 
This is the “Bet One Credit” button and it is dead in the sense that the spring doesn’t seem to work or isn’t there. While disassembling it, I noticed that this is the only button on the deck where the lamp body had been pulled away from the switch body and was dangling.
 
The other interesting aspect was that this was the only deck button where the switch body and microswitch were rotated in an 180 degree orientation when compared to the other buttons.  I have not fully disassembled it yet, mostly because it is going to be a very tight space to solder that wire back. The plunger doesn’t seem to make contact with the microswitch but my view is limited due to tight space. Either way, I have new buttons coming. I have never installed these before and I want to make sure of a few aspects.
 
The splicing and orientation seems odd so I am asking if it is ground and would the orientation lend itself to being the reason that it is not working?
 

[rokgpsman]

I'm pretty sure that the green wire that is daisy-chained from one switch to the other is the safety ground wire, it eventually connects to chassis ground at one end of the green wire. You can follow it over to one side and verify this by seeing if the end has a lug that is screwed to the metal chassis. The green wire doesn't have to be connected to anything for the buttons to work, it is there just in case a short were to happen in the machine and the player might get shocked. This is electrical requirements by UL and a good practice, even though the buttons are plastic so it is hard to imagine how someone would get shocked from the player pushbuttons.

The green wire is connected to a metal post on each button. That green wire is like the 3rd prong that's a little longer than the other 2 prongs on a 120 volt appliance electrical cord, nice to have for safety reasons but not required for things to work. Some people remove the green wire to get it out of the way when working on the buttons, then they never put the green wire back.

There is also a pair of wires connected to each button microswitch. And there is another pair of wires that connect to the button to light the little bulb inside, if the button is the type that has a bulb.

So all in all, you just need 4 wires to the button at most.

[rokgpsman]

If you disassemble the pushbutton you will see how it works. I think the top pops off and underneath is the bulb. There is also a spring in there somewhere that pushes the top part of the button upward. When the button is pressed the bottom part pushes against the microswitch to activate it. The mpu circuit board is what turns the button bulb on and off. I think the button will only light up when pressing that button would be a valid choice for the player.

Be gentle with these buttons, the plastic can get brittle from age.

[knagl]

On my PE+ video poker machines (same generation as the S+), there is a green ground wire that is, as rokgpsman indicated, daisy-chained to all the buttons.

The really amusing thing about it?  That metal post on each switch that the ground wire connects to?  ...it just goes into the plastic of the switch assembly and terminates there.  In other words, it doesn't do anything.

[rokgpsman]

Yeah, I think that green safety wire is only there because of some technicality in getting a UL or CSA approval for the machine. The entire metal chassis of the machine is already connected to power safety ground back where the power cord comes in. And since the buttons are plastic there isn't a lot of danger with them shocking someone.

Odd, IGT could have saved thousands of dollars by not installing the green safety wires to the buttons. 
So the only reason to do it was because they had to in order to meet elec code requirements.

[knagl]

Yeah, I think that green safety wire is only there because of some technicality in getting a UL or CSA approval for the machine.

That was my suspicion as well.  But man, that plastic is well grounded!