I have a defective Compaq presario 5000 power supply model no. HP-U250XCS3, it has a 24 pin main
connector, which does not conform to the ATX
power supply specification. I need to know the voltage associated with all the wires on the connector, so I can modify a standard 20 pin ATX power supply and use it to power up the computer.The color coding does not conform to the color coding of a Standard ATX power supply. Any help will be appreciated
abeza

It's probably easier (& safer) to buy a convertor - if you're in the UK then Maplin do them for about £3, I'd guess Radio Shack in the US would do them as well.

"I know that I'm mad - I've always been mad..."

Thanks Johnr for your reply, I am aware of the 24 pin to 20 pin converter. Since the HP-U250XC3 does not conform to the ATX power
supply specification, in terms of wire color coding and wiring of the connector,the converter will not be applying the proper voltages to the main connector of the motherboard. I guess Compaq designed their system so you have to buy the power supply from them. I have a few new ATX power supplies and if I had information in terms of what the D.C. voltages and signals are on pins 1 through 24 of the HP-U250XC3, I would be able to modify my new ATX power supply and use it to power up the computer.

Here is complete information for converter/adapter generic atx 20 pin
for Compaq Deskpro EN Series (24 pin)...
Note: Still some bugs, but work fine.

Ahh, I not speak english, but I understend
your problem, because I haven similar trouble and little review to electronics
diagrams, I found the next tips:

(In natal languaje; Spanish)

Conversion Avanzada:

Con esto se hace casi compatible una fuente generica 20 pin atx con una fuente
propietaria compaq PIII, se corta el pin 8 PWROK, (cable gris) y se ponen en
corto el pin 2 (3.3V cable naranja) con los pines 21, 22,(estos pines son los
del lado derecho del conector y quedarian sin conectar) pero haciendo el corto
con el pin 1 o 2 (3.3V) con esto se detecta la RED, y el sensor (temperatura).
En Bios seleccionar "After Power Loss" Always ON.

Bugs:

1.-Se tiene que apagar desde el switch de la fuente porque windows no la
apaga automaticamente.

Conversion Basica:

Cortar el pin 8 PWROK (cable gris). dejar 4 pines restantes sin conectar.
En Bios seleccionar "After Power Loss" Always ON.

Bugs:

1.- Se tiene que apagar desde el switch de la fuente porque windows no la
apaga automaticamente.

2.- No se detecta la tarjeta de Red, Ni el Sensor de temperatura.

This message is typed with:

Compaq Deskpro EN 1GHz, 256KB, 133 MHz
RAM 512, I used a Generic power supply since december 2004, and not problems
with OS, Win XP, Knoppix, RedHat 8, run perfectly.

Good luck!