Won't power up in the morning.

[Alan Westrop]

The last three days, I have had a problem when switching on my PC
first thing in the morning. Once it has successfully booted, it has
worked the rest of the day without problem, including when it has been
shut down for an hour or two and then rebooted.

The symptoms are that for the first few attempts to switch it on, it
switches itself off again in less than one second. Then for the next
two or three attempts it stays on for about three seconds before
switching off. Finally it boots up successfully. The power has to be
switched off at the mains between each attempt or nothing happens at
all when the button on the front is pressed.

The machine is about 3 years old, 1.2G Athlon.

I guess its the power supply, but thought I would see if anyone can
confirm this or make a better suggestion.

Thanks for any help.

Alan

 

[kony]

The last three days, I have had a problem when switching on my PC
first thing in the morning. Once it has successfully booted, it has
worked the rest of the day without problem, including when it has been
shut down for an hour or two and then rebooted.

The symptoms are that for the first few attempts to switch it on, it
switches itself off again in less than one second. Then for the next
two or three attempts it stays on for about three seconds before
switching off. Finally it boots up successfully. The power has to be
switched off at the mains between each attempt or nothing happens at
all when the button on the front is pressed.

The machine is about 3 years old, 1.2G Athlon.

I guess its the power supply, but thought I would see if anyone can
confirm this or make a better suggestion.

Thanks for any help.

Alan

The power supply would be shutting down the system, but not
"necessarily" because it is to blame for the actual problem.
It probably is the problem itself if one were to weigh odds,
but not necessarily. Take voltage readings if possible.
Examine the motherboard for vented capacitors.

During this period in the morning, is it possible the
machine is colder than usual?

You might examine all mechainal things... the movement of
the power switch, whether the cards, cables, memory, etc are
well-seated and aligned. Generally these things wouldn't
work themselves out to the point where it shuts the system
off though.

 

[Ray.Milne]

The last three days, I have had a problem when switching on my PC
first thing in the morning. Once it has successfully booted, it has
worked the rest of the day without problem, including when it has been
shut down for an hour or two and then rebooted.
snipped.

The machine is about 3 years old, 1.2G Athlon.
I guess its the power supply, but thought I would see if anyone can
confirm this or make a better suggestion.

Thanks for any help.

Alan

Do you have the shut down set in the bios for when the CPU fan
speed/temperature is under/over setting.
I had that when I replaced my CPU cooler.
Had to drop the fan rpm from 2000 min to 1000min.

Ray.

 

[afwestrop]

Thanks for your suggestions.

I opened the case and everything looked OK and properly seated.
Powered off and restarted a couple of times without problem.

This morning the problem returned. I can see the fans start, but the
system switches off in less than one second.

I wondered if it might be the switch - it feels and sounds OK but it
does have the ability to power the system down.

I tried connecting a switch mounted in another PC to the jumper on
the motherboard, and it booted OK straight away. Couldn't try the
reverse as the cable wouldn't reach the jumper in the other PC.
Still, I think I am on to something. Do you think this is possible?

Regarding temperature, it would be slightly colder overnight, but
back to normal by the time I tried to boot the PC.

Thanks again,
Alan

 

[kony]

Thanks for your suggestions.

I opened the case and everything looked OK and properly seated.
Powered off and restarted a couple of times without problem.

This morning the problem returned. I can see the fans start, but the
system switches off in less than one second.

I wondered if it might be the switch - it feels and sounds OK but it
does have the ability to power the system down.

I tried connecting a switch mounted in another PC to the jumper on
the motherboard, and it booted OK straight away. Couldn't try the
reverse as the cable wouldn't reach the jumper in the other PC.
Still, I think I am on to something. Do you think this is possible?

yes it's quite possible, but you mentioned that it would
start later in the day OK, so you'd be the better judge of
whether the replacement switch solves this in the same,
morning scenario.

Regarding temperature, it would be slightly colder overnight, but
back to normal by the time I tried to boot the PC.

Well yes and no... the box gets cold as it's surrounding
when turned off, but being off and having been in cold
surroudings it's a partially enclosed air space when the
surrounding room temp rises... plus being off all night it's
bound to be colder than having been running. Even so it
seems like a minor difference, the temp factor may not
matter as much as power supply (would seem next most likely
culprit after power switch).

 

[afwestrop]

It wasn't the switch - eliminated this by swapping with the
reset button.

Found that leaving the power on at the mains avoided the problem,
but after a week it started happening again.

Bought and fitted a new power supply, and the PC has booted first time
the last three days, so hopefully that was the culprit.

Thanks again to those who made suggestions.

Alan