ATX computer power on modification possible?

Xamindar · Post by **Xamindar** » Thu Apr 28, 2005 5:47 pm

Let's see, I set this old compaq pentium 400 up to be a firewall for my home network. It all works great, until the power goes out. There are no bios options to have the machine power up automaticaly or as last state.

So my question is, can this machine somehow be modifies so it will just boot up when power is applied to it? What about sticking a jumper where the power switch goes on the motherboard?

Thanks guys.

Krom · Post by **Krom** » Thu Apr 28, 2005 5:55 pm

Actually, shorting out the correct two wires on the ATX connector should work, jumpering the power button connector won't tho, that would only turn the system off.

Edit: yeah, I just remembered I used an old 300W ATX PSU to drive that monster 2 amp fan I have on my water cooler before I hit gold with an even older AT PSU.
http://xtronics.com/reference/atx_pinout.htm
Short the the wires from pins 14 and 15 and the PSU will power on even if it isn't connected to a computer.

Krom · Post by **Krom** » Thu Apr 28, 2005 6:11 pm

By the way, I never tested that method actually using the PSU to run a computer, only to run fans and drives not connected to a computer, I don't know if it would damage a motherboard or not, you have been warned.