The Pin-out for the ATX Power Plug

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The Pin-out for the ATX Power Plug

Postby Karlsweldt » Tue Jan 24, 2006 10:23 am

Standard ATX power plug.. Dell's connections are different!

............Pin 1............Pin 11
Orange +3.3...|0..0|....+3.3 Orange
Orange +3.3...|0..0|....-12 Blue
Black gnd........|0..0|......gnd Black
Red +5............|0..0|....PS_on Green
Black gnd........|0..0|......gnd Black \\ (latch)
Red +5............|0..0|......gnd Black // (latch)
Black gnd........|0..0|......gnd Black
Gray PSgood...|0..0|......-5 White
Purple +5 SB...|0..0|.....+5 Red
Yellow +12......|0..0|.....+5 Red
.............Pin 10........Pin 20

For Dell non-standard: Pin #s the same.


............Pin 1............Pin 11
Red +5.................|0..0|......PSON Gray
Black gnd.............|0..0|.......gnd Black
Red +5.................|0..0|......gnd Black
Black gnd.............|0..0|.......gnd Black
Orange PSgood...|0..0|.....-5 White \\ (latch)
Purple +5 SB.......|0..0|.......+5 Red // (latch)
Yellow +12..........|0..0|.......+5 Red
Blue -12..............|.0..0|.......+5 Red
Black gnd............|0..0|........(blank)
Black gnd............|0..0|......+5 Red
.............Pin 10..........Pin 20

For testing a PSU without a mobo, it is required to have a minimum load on the +5 volts and +12 volts rails. Otherwise, the PSU will not regulate properly. A minimum load of around 5 amps each is required. A wire-wound resistor of 2.5 ohms, 20 watts would be good for the +5 volts, and a 5 or 6 ohm variety would be good for the +12 volts. A common auto headlamp with dual filaments could be used as a sub. The "common" terminal is the ground lead. The resistors will become very hot, in a short time! The +3.3 volt source will regulate properly, as long as the +5 volt source is loaded. A 21 to 35 cp lamp could also be used, in 12 volt type.
To energize an ATX PSU, note the PSON control wire.. it controls the PSU's active state. Use a section of ordinary paper clip to bridge the back of the plug's wires, from the PSON to a black lead. The PSU will remain on for as long as the bridge is in place. If no suitable load is impressed on the sources, then the PSU may turn off and require up to 5 minutes to reset, with no line cord plugged in.
Karlsweldt
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