Thank you for being a valued part of the CNET community. As of December 1, 2020, the forums are in read-only format. In early 2021, CNET Forums will no longer be available. We are grateful for the participation and advice you have provided to one another over the years.

Thanks,

CNET Support

General discussion

cpu turns off in 1 second

Apr 24, 2017 2:09AM PDT

when i switch on my cpu its turn off in 1 second. but when i disconnect my harddisk and dvd writer and switch on my cpu,it runs well... i tried my psu on other motherboard it works well..and i also use new psu on my cpu but the same problem occurs.. one more thing...when i disconnect my p4 power connector and connet harddisk and dvd writer then cpu runs well but nothing displays on monitor...pls help

Discussion is locked

- Collapse -
I'm guessing that this is a
Apr 24, 2017 2:31AM PDT

newly built computer and you or a friend built it ?
Tell us about it ...

- Collapse -
i works well 3 days ago
Apr 24, 2017 1:26PM PDT

not new built... it works well before... i also check all the connections well as described in some sites...no loose connections, no rusty or leaked capacitor,etc...

- Collapse -
Try it like The Dead PC.
Apr 24, 2017 1:29PM PDT

As a tech you use a method (google The Dead PC) to downsize it and even move the motherboard to cardboard to see if just a few parts turn on.

-> In short, that's how it's done.

- Collapse -
Re: connector
Apr 24, 2017 2:37AM PDT

And what's on that p4 power connector?

Better tell the whole picture, including model numbers.

- Collapse -
ASUS P5KPL-CM
Apr 24, 2017 1:44PM PDT

ASUS P5KPL-CM is printed on my mother board and my processor is intel pentium...

- Collapse -
3 days ago? Or 7 years ago?
Apr 24, 2017 1:57PM PDT

Didn't that board ship in 2010? Always tell the full story.

- Collapse -
Might be a short circuit somewhere
Apr 24, 2017 7:23PM PDT

Try to disassemble the board and the psu for some cleaning and preventive maintenance first. Assemble and see if will make a difference. There might be a short circuit somewhere and your system is protecting the components.

- Collapse -
CPU runs well but nothing on monitor
Apr 25, 2017 2:14AM PDT

If nothing displays, are you sure the PC even booted? It could be that just the fans are running. As well, trying the power supply on another PC isn't proof as a weak PS may do that if the other PC isn't drawing as much current as the one you're having trouble with. The easiest way to determine if the PS is the culprit is to replace it with one of higher wattage than the original. If you had a DVM, you could do the green wire test and see if all voltages came up within range but that's not always definitive either. I've seen the scenario you've mentioned and, while it could point to the HD or DVD device, it turned out to be the PS. While these drives don't draw a lot of current when running, starting the motors does draw a lot more than keeping them spinning.