Last night I noticed by accident that if I, with a very light tough, I dragged my finger across the metal side rails on my PinBot I could feel a very subtle tingle. I only felt it when I would *move* my finger across the metal and it was barely noticeable. I was standing barefoot on my basement floor when I noticed it. First thing I did was placed a socket tester in the service outlet and it showed that the machine was properly grounded (at least at the outlet). Next thing I tried was a continuity test of the side rails to the rest of the machine and that checked out. Next thing I tried was a continuity test to the side rail of the machine I have next to PinBot, since both machines obviously share common ground. Funny thing is that the continuity tester chirped and pulsed in a pattern almost identical to a typical digital alarm clock alarm. Almost like continuity was 'almost there' for 3/4-second, then not present for 3/4-second, then present again, repeating. I then checked A/C voltage between PinBot's side rails and the grounded side rails on the adjacent machine. Oddly I got a reading of around 50V AC. I used a wire to short PinBot's side rails to the adjacent machines grounded side rails and nothing out of the ordinary happened except the 'tingle' went away when touching the metal while the wire shorted the rails.
Any idea's why this is happening? Is this simply a sign of some place in the machine where the ground strap perhaps has some electrical resistance from a loose wing nut or dirt/corrosion/rust?