Hardware Reference
In-Depth Information
All AT/LPX power supplies that use the P8 and P9 connectors have them installed end to
end so that the two black wires (ground connections) on both power connectors are next
to each other when properly plugged in. Note the designations P8 and P9 are not fully
standardized, although most use those designations because that is what IBM stamped on
the originals. Some power supplies have them labeled as P1/P2 instead. Because these
connectors usually have a clasp that prevents them from being inserted backward on the
motherboard's pins, the major concern is getting the two connectors in the correct orient-
ation side by side and also not offsetting by one or more pins side to side. Following the
black-to-black rule and ensuring they are on-center keeps you safe. You must take care to
ensurethatnoremainingunconnectedmotherboardpinsexistbetweenoroneithersideof
the two connectors after you install them. A properly installed connector connects to and
covers every motherboard power pin. If any power pins are showing on either side of or
between the connectors, the entire connector assembly is installed incorrectly, which can
resultincatastrophicfailureforthemotherboardandeverythingpluggedintoitatthetime
of power-up.
Figure 18.19
shows the P8 and P9 connectors (sometimes also called P1/P2)
in their proper orientation when connected to a motherboard.
Figure 18.19
The P8/P9 power connectors (sometimes also called P1/P2) that connect an AT/LPX power
supply to the motherboard.
