power button dont need

[lovehack]

I'm new to circuit board tech, so please help, I have a small computer at home an want to take off the power button, so when I plug it in the wall, it auto turns on the single board computer, is there a way to solder the board.

thanks.

[email protected]

 

[OLIVE2222]

Hi lovehack, welcom to this forum.

Normally you just need to short the power button (I guess a momentary contact one).
This should correspond to the green wire (power on) of the ATX power supply .

Olivier

 

[lovehack]

I'm using a Cerf board 250, its not a ATX mother board, they are really small Linux servers, I'm using 5v 400ma cord, but the power button is going,,,I thought I could just cross a wire or 2

 

[OLIVE2222]

Ok Lovehack no idea about the Cerf board 250 if it's push button powered give a try to the short solution anyway, will not hurt. Hopping that the board will not power-up then power down because the button stay in "pushed" position.

Olivier

 

[(*steve*)]

Some boards have power buttons that don't respond well to being always closed.

Some boards also have options in the BIOS to change the way they work.

One board I used had an option which, if set, would cause the computer to go intot he same state as it was when power was removed. i.e. if it was on, it would turn itself back on; if it was off it wouldn't.

On some motherboards there is no way of doing this and you either give up, or create a piece of hardware that presses the power button a few seconds after power is applied.

 

[lovehack]

OK I can understand that, so I will just have to buy a switch and install it on the board,,I didn't want to take that route,, but we will see nExt''

thanks for the help
my fellow teckies

I can get the hang of this forum thing,,,it beats tech support any day

 

[(*steve*)]

One possible hack is to connect a capacitor across the switch contacts with a high value resistor in parallel.

This may be enough to simulate a press of the button when power is applied.

You'd probably have to employ some trial and error to get the right value components though.

If you can measure the voltage across and the current through the switch (connect a multimeter first in voltage mode, then current across the switch). With these 2 measurements we may be able to come up with some starting point.

The above only applies if permanently closing the switch or the BIOS route yield nothing.