Computer Powers On then off then on and stays on. On startup

B

bschaffer

New Member
Hey,

This isnt a huge problem (I hope it hasnt done anything to any of my components). But, here we go:

When I push the power button on my case, my computer turns on for like 5 good seconds, then it turns off for like 3 seconds and then comes back on and loads up correctly.

I built this system myself and know everything about it. Im running Vista with SP1.

I can list my system specs if you need them to help me trouble shoot this. The reason Im posting is because I couldnt find ANYTHING on the web about this particular problem.
 
It wouldn't be turning off fully but simply starting up the post tests. When first turning any system on the lights will flcker and any on the keyboard will briefly flash. Then you see the first post screen with the option to enter the bios setup or the full screen logo of the board manufacturer on a custom build.

That can easily be disabled in the advanced section of the bios for simply seeing a black screen with all tests displayed for drives and the memory count. I trust this is your first or one of the first you built yourself.
 
this is the first I built myself, and thanks for your help,

but its not simply flickering, I know my computers and this isnt right.

all of the power goes on and off. ive watched with the case side off and when I push the power, ALL of the fans/lights come on, then when it goes off after 5 seconds all of them go off and stop and then three seconds later it all comes back on and starts.
 
If you feel that's there's a hardware problem then you have two items to consider.

The first would be a wimpy power supply seeing a drop since the largest pull is generally seen when a system is first started up and the post tests are conducted. A supply lacking a good regulation or simply not adequate seeing enough amps on the rails for the build would be the thought there.

The second would be a possible board fault being realized like a weak cap or other component that could give out in a short time. The first of two boards on the current build simply quit after the first three days of use.

Back in 2006 a friend was puzzled at why he couldn't even get a new build to run having received two bad boards in a row. The third was a different model of the same seeing lasting results!

The plague of bad caps has been an item for several years at this point. But recheck all power connections before assuming any hardware fault first in case a wire is lifted off somewhat or a connector needs to replugged in to see that fully inplace.
 
no ive got the intel dx48bt2 which i was told would be a very reliable board. And I have a Corsair 750TX psu (750watts) which I read would also be very reliable. I will pull everything and check all power connections and maybe leave some of the 6 case fans off and see if it still hiccups.


Thanks a lot for the help PC eye and good information. Could you tell me if this could be damaging any of my components, all the powering on and off. The computer runs great after its booted.
 
If this is happening in the first 5 seconds of you turning on the computer your OS is irrelevant because the computer hasn't even started getting to the OS at that point.

If the computer is doing two different things each time in a sequence that it powers on, it's probably supposed to do that. If the computer starts populating the RAM and hard drives for five seconds, goes kaput, then comes back on and starts populating the RAM and hard drives again, you've probably got a problem. Otherwise it's likely normal functioning for that motherboard.

Powering a component on and off doesn't hurt it. Internally, that's all computers ever do, is power specific lines on and off and feed them into transistors that'll power other lines on and off. Getting it hot and then cooling it off can cause chip creep, but it's not going to get hot in five seconds. I would be surprised if this damages your computer components.

The only thing I might be worried about is the hard drives. I understand spinning them up and down frequently can wear them out somewhat faster than normal, so if the hard drives are revving up, then stopping, then revving back up, you may see slightly shorter hard drive lifespans than expected from that machine.
 
Ive got a seagate 500gb HD thats a 32mb cache NCQing with 3gb/s SATA. Its made for servers and has a very long life expectancy.

e837 thanks for your valuable info, but do you have any idea what could be causing this?
 
Like I said, unless the computer is checking for RAM and hard drives both times, I assume it's supposed to go through a phase that appears powered off during a normal boot.
 
Either that or there some form of switching problem being seen with the board. When most systems are first started you hear the fans start amd lights for drives as well as for power and hard drive activity(leds) blink quickly followed by them then going dark only for a second or two to see the keyboard lights flash. The first post screen or logo then is displayed with only a second or two gap.

With a good supply by a brand like Corsair with the odd exception of a bad one getting out you would generally have everything covered. One of the better supplies won't wink on you while the system is starting unlike any cheapie generic or under powsred. Then of course your system information wasn't requested either.

Ruling out the supply checking to see if a connection or wire is loose or has a bad contact is a thought as a means of ruling out a more likely board fault being realized. Remember when a system first starts you see not only the largest demand on the supply but pull of power through the board at that time. Any weak component effects the power being distributed.
 
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