Power Up but no Boot up

  mosstoe 13:15 07 May 2006

Hi guys,

I recently built my machine and moved home. Before I moved it was running fine, but ever since i connected it all back up, I'm having strange power up issues.

From the start, if I just turn on the power using the switch on the PSU the CD Crive stats up, the PSU Fan starts up and the lights i have on the case light up. The Hard Drive and monitor do not however.

This only happens once i turn the PC on from the front of the case as you would normally expect.

Why does the machine 'half start' then before I press theon switch at the front??

Kind regards

  wee eddie 14:27 07 May 2006

Check all the connections again, pull them out and push them back.

I know that this sounds obvious. with no Post Beep, check the board.

  mosstoe 14:45 07 May 2006

All connections are ok, have tried this. what else do you think it could be?

  Gongoozler 15:19 07 May 2006

To clarify. Are you saying that when you apply power from the PSU switch the computer half starts, but after that the front panel switch works normally?

  woodchip 15:50 07 May 2006

PSU is up the spout, You need a New one

  mosstoe 17:21 07 May 2006

that's right, it half powers when I switch the PSU on from the back, which normally wouldn't do anything.

And then it boots up the hard drive once I press the on button at the front.

  Fruit Bat /\0/\ 19:08 07 May 2006

On an ATX PSU system power is constantly supplied to the board (provided the machine is plugged in and switched on at the PSU, the button at the front just puts a momentary signal to the motherboard.

The motherboard then signals back to the PSU which supplies full power to everything (direct Fans, lights etc..)

If you have the PSU switched off at the rear switch, when you switch back on peripherals are fed but not motherboard as return signal not yet supplied by motherboard.

IF fans lights not switching off when you power down the PC, check power options in windows and te BIOS.

  mosstoe 21:53 14 May 2006

Ok great,

Can you tell me how to check and change the bios settings?


  Fruit Bat /\0/\ 22:35 14 May 2006
  Gongoozler 09:55 15 May 2006

Hi mosstoe. If you want specific instructions on changing the BIOS settings for your computer, you need to tell us what motherboard you have. However, it seems to me that if the BIOS settings were right before you moved home then it is unlikely that they would change by themselves, however the vibration of the move could well have disturbed a connector or badly soldered component. The fans only need +12V to work, and the power light only needs +5V. It's still quite possible that the +3.3V isn't working and that is the one most of the motherboard uses. The PSU is the easiest thing to try, either borrow one or try a cheap one such as here click here

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