Pull the power cord before probing around!
The heatsink in the center of the power supply board has about -78V and it's DC. The amperage is unknown but 80V at 2A (fuse) would hurt a bit!
It might just kill you!
YOU HAVE BEEN WARNED!
You can't let go! Heart "zap" machines use DC !
For those of you who don't understand this, DC at high enough voltage and the right situation will cause your mussles to contract and stay that way.
I placed one of those zip lock freezer bags over the power supply while I was probing power connections. They are thick and non conductive.
You have no need to be probing around in there with the power on!
The 110V switch cables are better insulated, but why take the chance? Pull the plug!
PLEASE BE CAREFUL!
The larger heat sink off to the side of the power supply is grounded. The one I am talking about is the one that is almost centered within the board.