Why does my computer turn on, turn off, then on?

Question

I have never encountered a problem such as this one. I have a Dell Dimension 2400 Desktop. When I turn it on, It powers on for 3 seconds or less, then turns off by itself, then after 1 or 2 seconds, turns on automatically. I hear something but it doesn't sound like a beep; it's very faint. Also, there is no display. After it turns on fully, everything seems to operate normally on the tower. You can see the power light on, fans on, motherboard light on but no display. I have Windows Xp Pro and there is no video card. The monitor is plugged into the on-board VGA port.

Any ideas?

Answer 1

Try resetting CMOS through the CMOS jumper or by removing the CMOS battery for 20-30 secs. If display appears, press Del or F2 to enter BIOS menu. Load fail safe defaults, save and exit.

If problem persists, use a bare minimum set up. Disconnect HDD, FDD, CD drive, nothing on PCI slot and USB ports and just one stick RAM. This set up should be able to open up to BIOS menu. Reconnect the devices (PC off) one at a time. The device that brings back the problem is defective.

If problem still persists w/ minimum set up, the motherboard could be defective.

Answer 2

First clean the inside of your computer case. Using air and a vacuum cleaner.Look for hair and dust spyder webs etc and remove. Take a close look at where your power buttons conect to and your lan jumpers. Then plug your power back in and immediately after booting to your operating system run the best anti virus software you can afford Also run anti spy ware. Youll be surprised at how many problems you have and if not corrected how bad it will get.

Answer 3

If you try to turn off your computer and it hangs then you have softwares still running in the background, usually window automatically shutsdown any softwares but there are those that sometimes seem to not respond to well to Windows command, most of the time these softwares tend to be anti virus programs or anti spywares like Webroots, try to close all programs in your system before turning off the the computer such as spysweepers, msn, norton etc etc

Answer 4

Well, this isn't the first time I have heard of this. My laptop does the same thing, and so far nothing works. What I would suggest is that if you modified your hardware, try to remember what you touched, if anything. Static electricity could have fried your RAM, motherboard memory, or even your processor. You may need to replace either one or a few components. If this doesen't work, I would try contacting Dell or taking it in to a Computer store and see if they can help.

Answer 5

nate said it best

Also might have a faulty CPU fan. Most BIOS will shutdown the PC if the CPU fan is not operating correctly or not at all.

PSU could also be faulty. Can you get into the BIOS? If so see if the problem continues, and if so, it is more than likely a power supply issue.

Answer 6

This could be a few problems, Maybe your on-board video card went out... You have some bad RAM. your Processor is overheating... It sounds like 2 of those 3 put together. Especially if you're getting no video output...

Answer 7

its not a virus because:

you computer has to finish its POST (power on self test) before it loads ANY code from the hard drive. The test should catch any serios errors like what everybody else said.

Answer 8

I have had the same problem with my one I got it checked out and the solder on my motherboard had burnt out. Otherwise it could be bad Ram or CPU problems

Answer 9

lets hope its not a virus but if the problem persists make sure everything is plugged it and turned on properly maybe it could be a virus i could be wrong have a tech look at it

Answer 10

check the power button