- 12vdc

[xwrench3]

i have been chasing a "ghost" in my computer since i built (actually a total rebuild in the old case using the existing power supply) it last summer.  my computer desk has a place (bottom right corner) for the computer to sit. it fits in there nicely, and it is safe (from my nosy cumbersome dog). but if i have to move the computer, it will not start again until it is removed. as soon as it gets out of that spot, it will fire up like a champ.  one thing was suggested to me that made no sense, was the power supply. but as kind of a last resort, i checked it out. everything checks out fine, except the -12vdc wire, which reads -10.3v. since there are multiple black ground wires, this reverse polarity seems quite odd. exactly what uses this, and what does it do?  fyi, i have given up on using the designated computer spot in my desk, and the computer works excellent.