stolen from
http://www.hwkb.com/Uwe/Forum.aspx/h...in-motherboard

Quote--------------------------------------------------------

Another instance of "Proprietary hardware." Does anyone know the
>voltage or purpose of each lead on such a Compaq PS versus a standard
>PS? I was wondering if such a standard supply could be modified to the
>Compaq requirements? Such as the extra leads on a Compaq might simply
>be additional leads with an already existing voltage elsewhere on the
>standard PS (i.e +3.3 volts).

I tried modifying one once, did what seemed appropriate by connecting the
rails of a standard ATX to the proprietary Compaq wiring harness, but it
didn't work... I even supplied the Aux. 3VSB power (via a 2nd external
power supply) that theirs has but it STILL didn't work. I might've gotten
it to work if I had the Compaq motherboard too but I didn't, the fellow
with the system was hundreds of miles away.

Anyway, here's the pinout on the original unit I had, compared to a std
ATX. The terms such as "fan_sink" and "onstby" aren't standard terms but
were silkscreened onto the Compaq PSU PCB itself.

Pin # STD ATX 12V Compac 5320US

<1> +3.3 VDC +3.3 VDC Brown
<2> +3.3 VDC +3.3 VDC Brown
<3> COM COM Black
<4> +5VDC +5 VDC Red
<5> COM COM Black
<6> +5 VDC +5 VDC Red
<7> Com Aux Gnd (from aux board) Grey
<8> PWR ok N/C
<9> +5V SB +5 (from aux board) Turquoise
<10> +12 VDC +12 VDC Orange
---------------------------------------------------------------
<11.1> +3.3 VDC +3.3 (from aux board) Pink
<11.2> 3.3V sense
<12> -12 VDC Fan CMD White w/ Red Stripe
<13> COM +3.3 VDC Brown
<14> PS - On +5 VCD -12V? Blue (-12V)
<15> COM COM Black
<16> COM Power On White (ONSTBY)
<17> COM COM Black
<18> -5V COM Black (2nd wire, black
RTNRS)
<19> +5 VDC COM Black
<20> +5 VDC +3.3 VDC Brown
<21> ------ +5 VDC Red
<22> ------ +5 VDC Red
<23> ------ +3.3 VDC Sense Brown (3VRS)
<24> ------ Fan_sink White w/ Blue Stripe