Power Up Problem

[samtay]

Hi,

My PC is not able to power up. It was working fine a day before. And I did not do anything to my PC. Here's how the problem goes.

I switch on the main switch... switch on the PC.. the power led lights up a for a while(1 sec).... then went off....

I tried switching on again.... nothing happens....

I switch off the main switch... then switch on the main switch.... try switching on the PC again..... the power led lights up for a while(1 sec) then went off...

I tried switching it on again... then nothing happens.

seems like everytime i restart the main switch... the power led did light up a while but gone after a while..... anyone could tell me where the problem lies?? and how should i go about resolving the problem

[Sylvander]

Download a copy of my diagnostic flowcharts from here
www.erniek.eclipse.co.uk/downloads/sylvanderdiags.zip
and print them to leaf through.
Begin on the STARTUP chart.

I would say your PC is not "dead" [an LED lights up], so we're talking NO POST here.
As instructed on the NO POST chart, "Disconnect all peripherals and system adaptor cards..." for a "bare-bones boot".
Some item of hardware is causing a problem and the PC is protecting itself by shutting off the supply of power from the PSU.
Removing as many hardware items as possible will reduce the number of suspects.

Try that as a 1st step and we'll take it from there.

QUOTE
System [BIOS] Boot Sequence
The system BIOS is what starts the computer running when you turn it on. The following are the steps that a typical boot sequence involves. Of course this will vary by the manufacturer of your hardware, BIOS, etc., and especially by what peripherals you have in the PC. Here is what generally happens when you turn on your system power:
1. The internal power supply turns on and initializes. The power supply takes some time until it can generate reliable power for the rest of the computer, and having it turn on prematurely could potentially lead to damage. Therefore, the chipset will generate a reset signal to the processor (the same as if you held the reset button down for a while on your case) until it receives the Power Good signal from the power supply.
2. When the reset button is released, the processor will be ready to start executing. When the processor first starts up, it is suffering from amnesia; there is nothing at all in the memory to execute. Of course processor makers know this will happen, so they pre-program the processor to always look at the same place in the system BIOS ROM for the start of the BIOS boot program. This is normally location FFFF0h, right at the end of the system memory. They put it there so that the size of the ROM can be changed without creating compatibility problems. Since there are only 16 bytes left from there to the end of conventional memory, this location just contains a "jump" instruction telling the processor where to go to find the real BIOS startup program.
3. The BIOS performs the power-on self test (POST). If there are any fatal errors, the boot process stops. POST beep codes can be found in this area of the Troubleshooting Expert.

Perhaps no "Power Good" signal is being got from the PSU?

[Toadman03]

Ive had something like that hapen once. It drove me nuts so i had to go to a local comptuer shop. They tested the mobo outsid the case and it worked. They told me the case had lost its ground somehow. I put everything back in a new case and it started right up. I still dont get the case losing its ground. They said it had something to do with static shorting the board. But it worked? You might want to try that. You dont need any hard drives or any of the power switch power led resetswitch etc plugged. Just the video card and plugh in the keyboard and mouse. To start it just touch a flathead screw driver to the two power switch pins

[Naykon]

samtay were you able to resolve the problem?

i'm having exactly the same issue

i've ordered a new PSU as i thought that my PSU had died, its strange how everything starts to power up for about a second and then just stops, if anyone can help further i'd appreciate it,

thanks