Test switch help

I have a consolised 4-slot. The Test switch hasn't worked since I bought the thing and while this isn't a problem due to the Unibios, it is bothering me and so I decided to take apart the board to investigate. I've have found that one cable runs from the switch to the JAMMA edge, which I figure is correct. The other cable runs from the switch and is soldered to the metal casing of the board. I'm not sure that this is correct, especially as it doesn't work.
Can anyone help e out as to where that second wire should be soldered to? I'd greatly appreciate it.

The other wire should probably go to the ground.....not the case...

what Jamma pin # does the other wire go to?

The first wire goes to pin M, second to the inside of the casing.
I have also just found another wire coming from pin R, but it gets lost somewhere inside the board. There isn't a button for service so I have no idea as to why its there.

pin m is the test location...

just wire the other wire to a ground point....

Any other ground point at all? A, B, 1 and 2 are already used. I have E, F 27 and 28 left open. Do I have to use 27 or 28 on the parts side as M is on the solder side?
And can I solder the wire at R to another switch and add in another ground for a service switch?

J0e Musashi said:

Any other ground point at all? A, B, 1 and 2 are already used. I have E, F 27 and 28 left open. Do I have to use 27 or 28 on the parts side as M is on the solder side?
And can I solder the wire at R to another switch and add in another ground for a service switch?

Click to expand...

Any of those points will do, or just ground the metal casing, it must have been grounded at some stage for the test switch to work, the mobo has probably been swapped in the cab and whoever did it couldnt be arsed to reconnect the ground point.