ATX Power Supply question

[Jubin]

I just swapped an AT power supply for an ATX unit. My motherboard supports both, although I have no documentation for it. The AT P/S had an A/C power switch on the front. ATX P/S's need a soft start from the motherboard. Since I have no docs, I don't know which jumpers need the momentary switch across them. My question is this: what is required at the ATX plug to make the P/S go on? A short across one or more pins? How can I turn on the supply without even plugging into the motherboard? I don't mind a solution that involves yanking the plug out of the wall as the only way to turn off the unit! Appreciate any help or info.

 

[Tbarney]

Yes, there are 2 pins on the mobo that need to be shorted to turn on the power. the operating system should turn it off if your BIOS supports it. If you son't have a manual which shows the power switch pins on the motherboard, do to the manufacturers website and look it up

 

[TyrantSSV]

If you want turn on the PSU without even plugging into the motherboard, you can short the green wire with any black wire on 20-pin connector of PSU. The supply will work while these pins are shorted and shuts down when opened.

Of course, find the documentation for the motherboard and use proper way to control the PSU is more correctly.

 

[paparazi]

If you look very closely at the printed circuit board next to the front panel header connections it maybe possible to see some information/abreviated imprinted on the board, to indicated power switch location.
something like ps or pwr.
Because you have an AT case that front ON/OFF switch will be no good but it shouldn't be too much of a job to either replace it or drill and mount a sprung contact type switch and route two wires to the switch header.
A door bell type switch that you press to make contact then release. Martin Please let members know if there advice has helped any.

 

[Jubin]

Thanks - Shorting the green wire to the black did the job. Looks like I can connect these wires to the old switch if I can't find the motherboard docs. However, as you point out, the latter is the proper way to go. Thanks for all your help.