I am in the process of swapping out all of the cr@ppy 2-prong power cords in a bunch of EMs, and as well putting in switches in the ones that have the hokey mains voltage going through the flipper and require opening up the baryswitch in the center to turn off!

For the stock-switched games (i.e., stock 2-prong cord), I've been tying in the hot line to the existing cord line that goes immediately to the fuse before going to the switch, and tying the neutral to chasses of the transformer & switch and to the coin door.

I suppose that I could also tie into the 4 brackets that surround the coin door (for Bally & Williams) and the side rails & legs, but I've read that that could be counterproductive. (So far, I've looked at Williams OXO, and it seems to have this grounding already in, with me just having to tie in the ground to a eye-terminal in the back.) Bally Wizard! has the 3-prongs already, but also the mains power going to the switch, so I plan to throw that out and just short the Hold relay so that it actuates upon power switch on, like the other switched EMs I have.

For the non-stock-switched games, I've been doing the same, but adding in the switch between the fuse going to the hot mains, which seems to mimic what 3-prong, grounded EMs did.

Am I doing this right, or should I be doing this differently? Thanks

The website asked me to enter the games, but when I tried to do that, it simply submitted the thread. The games are:

stock-unswitched:

Bally Rocket III
Bally Dixieland
Bally On Beam
Williams Apollo
Gottlieb's Diamond Jack

stock-switched:

Gottlieb's Hot Shot
Gottlieb's Jack In The Box
Gottlieb's Outer Space
Williams OXO

Yes, I might have improperly named the relay. I plan to think through carefully the modifications to get rid of the "mains voltage to the flipper" issue, and post my conclusions here, to get everyone's input.

It seems that as per your description, for the stock-unswitched games, I'm doing it like BBB: the hot goes into a line of another power cord (call it cord #2) (for the #2 cord, I use a cheap standard grounded computer power cord rated at 10A with the ends chopped off - actually each cord being 10' gives me a pair of 5' long cords) that then goes to the switch and with the return going back and being connected to the line that goes to the stock wiring that goes directly to the main fuse, and then on to everything else. The stock wiring is mains-fuse-STUFF-mains (for the Bally titles, STUFF is simply the transformer, while for the others, STUFF contains other stuff), so the switch simply changes it to mains-SWITCH-fuse-STUFF-mains.

However, it also seems that for the stock-switched games, the manufacturers did it as AAA, and so I am doing it like this because, to quote Homer's advice to Bart when Homer thought that he had eaten a deadly piece of sushi, "it was like this when I got here". This begs the question of whether one should rewire stock-switched games to transform them into BBB; that seems to be going against the original design.

I too like the idea of having a master switch that completely shuts off any power. Typically, the only way I do any live stuff is to first power up and then power down the game - noting that the general illumination lighting is on when powered up - to make absolutely sure that the power is off, then I put my alligator clips on wherever I'm trying to measure a current/voltage, and then turn on the machine and start it up into game mode and actuating whatever I need to do to get that current/voltage reading. I say typically, because sometimes when the game doesn't start with the credit button or some other type of main sequence thing, I will take a plastic or wooden rod and actuate the start or hold or game over, etc. relay.

While I am inquiring into adding a switch, this brings up the question if it matters whether the hot or neutral goes into the main fuse (or switch then fuse, as it were). I had always thought that it doesn't matter since the line is AC, although I have a hunch that the power plant (or at least the distribution substation) grounds the neutral, so it could make a difference.

As a sanity check when I finished, I plan to pop the main fuse and then do a continuity check on the power cord plug hot - which (when looking at the plug) would be the left, which mates with the outlet right (when looking at the outlet), which is the hot line (i.e., for NEMA) - to the fuse holder tab such that there is continuity in one position of the switch, but no continuity for the other position; this will qualify that I've hooked up the hot properly. Of course, I will also do a continuity check from the plug ground to the switch, transformer & any other place that is to be grounded - and as well, a continuity check (i.e., insuring that there is NO continuity) from the prongs of the plugs to the aforementioned places that are not supposed to be connected.