Computer Won't Power Up

[Guest]

I have a custom built PC that has a nagging problem I can't figure out.
Whever the machine is without power for an extended time, either unplugged,
or a power failure at the house, the machine is very difficult to re-start,
once power is re-supplied. The last time this happened, a power failure at
the house that lasted for a whole day, I managed to get the machine to
finally re-start, but only after holding the power button on the case down
for 5 minutes. Last night the machine was unplugged for several hours and
today I cannot get it to start, no matter how long I hold the power button
down.

Is there some kind of a battery that could drain if a continual power stream
to the computer is not available? Is this a possible power supply problem or
is something perhaps in the system telling the machine to go into some deep
hibernation? I have made sure time and time again, that hibernation is turned
OFF in the control panel.

any ideas? Thanks

 

[Tony Williams]

There is a small battery on the motherboard that keeps the bios alive that
may be flat?
Tony

 

[Guest]

The small battery on the motherboard that keeps the bios and clock settings
would not stop the PC from working.

I would check your power supply or your power button.

hope that helps ?

 

[AJR]

Power on setting on an ATX MB (major MB is use today) is software
controlled - it is not a directly wired on/off switch. The MB has power
applied at all times (five volts)when the power cord is plugged in a socket
(a reason why set should be unplugged when serving the "innards") - when you
push in the off/on button, the five volts is relayed back to the power
supply and switches on the power supply. In fact most MBs today have a LED
on the board indicating presence or absence of the five volts. So - take it
from there.

 

[jaywitkow]

There is a small battery on the motherboard that keeps the bios alive that
may be flat?
Tony

I would do the following:

1. Pull the small, 2-position connector off the motherboard that goes
to the power button. With an ohm meter check to see if the power button
is closing the circuit. If it isn't, there is something wrong with the
switch. It's unlikely that there is anything wrong with the switch, but
you need to check.

2. Cut the two wires on the 20/24-pin connector that turn the power
supply on and connect them together (use a small wire nut). If the
power supply doesn't go on with the shorted wires, swap out the power
supply. If the power supply does turn on with the shorted wires you
will need to swap out the motherboard. Be sure to back up your hard
drive and use ESD procedures when installing a new motherboard.

If you don't want to buy a new motherboard, I suppose you could simply
limp along by using the switch on the back of the cabinet to turn the
computer on and off.