> My friend gave me his Presario saying the computer would shut down
> anywhere from a few seconds to a couple of hours after start up .
> My first thought was the power supply was going bad . I replaced
> with a known working power supply and the same problem occured.
> At that time I thought maybe it was the O/S so I replaced the hard
> drive and again the same problem .
> At that point I thought the on /off button
> on the front of the computer was bad .
> So upon pressing the start button and letting the computer power up
> ( fan starts turning) I disconnected the on/off button connector from
> the motherboard . The computer now runs fine . In windows I can
> restart the computer or put it in stand by mode with the on/off switch
> disconnected from the m/b . The computer simply cannot be powered
> all the way down without having to reconnect the on/off button
That is odd, it should shut down without the switch connected. Likely
the action of the switch hasnt been configured properly in the OS.
> and going through the above procedure to get it to boot again.
> My thinking perhaps incorrect is the on/off button
> is not a traditional switch in the mechanical sense .
I havent noticed one that isnt on that sort of case.
> Is there some electronic board ( m/b perhaps) controlling the switch that is
Looks like its just badly configured so that you cant shutdown
completely without using the switch and a bad switch.
The action of the switch is specified in both the bios and
in the OS with most systems. It may have got installed
with the wrong ACPI setting too, that may be why you
cant shut down completely without using the switch.
> and how difficult is it to replace .
Quite difficult to get one that will fit mechanically quite a bit of the time.
> I hope my friend can live with the computer
> in it's current set up but I doubt it.
Yeah, rather an awkward config.
It may well be possible to reconfigure the action of the switch
so it can be shut down completely without using the switch but
that isnt necessarily very useful if you want to run without a switch.
It should be possible to configure it to start on power on without using
the switch, but that might not be possible, depends on motherboard bios.