PC will not turn on?

[adaytay]

Hi all, this is my first time in these forums so please be gentle... :)

Looking through problems that have been posted here previously this looks like a great site, so hope you don't mind if I add a question?

I have an emachines 1.80 GHz machine with 128 MB DDR Ram and running Windows XP, and suddenly the machine will not turn on at all.

I have replaced the power supply with a similar one from another machine and although now the machine gets power, all that happens is that the power light comes on, and the processor fan spins - but it's still impossible to turn the power on.

Incidentally, when plugging this new power supply into the base it IMMEDIATELY gets power, and the power switch itself has no effect.

I'm guessing there is a problem with the motherboard? There are no beeps or anything like that, but it is impossible to turn the machine on, all that you hear is the sound of the fan.

Many thanks in advance,

Ad

[profdlp]

For starters, try resetting the BIOS. You should also check that the power and reset buttons aren't stuck (unlikely).

The next step would be to unplug the computer and disconnect or remove all of the following (if applicable):

Hard Drive(s)
CDROM Drive(s)
Floppy Drive
Extra PCI cards (Sound, Network, etc)
Printers, Scanners, etc.
All USB devices except Mouse and Keyboard

Ideally, all you want to have left attached to the MB is the CPU (with Heat Sink & Fan!), the RAM, a Keyboard and a Mouse, and the Video Card. If any of the devices are built into the MB (likely) don't worry about it.

At that point, give it another try. If it manages to start up alright, shut the computer off and add in the Hard Drive. If things continue to work, add in the other devices one-by-one, making sure to shut down and power off each time. If things suddenly come to a screeching halt you'll know that the device you just re-installed is the culprit. If none of that works we'll move on to other measures.

Good luck, and welcome to Short-Media. :)

[adaytay]

Hi Prof,

Thanks for the suggestions and the welcome to the site :)

I have flushed the BIOS by resetting the jumper and removing all power and the CMOS battery, however the same problem is still occuring.

Does this mean the mobo is fried?

Thanks,

Ad

[profdlp]

Did you try unplugging all the stuff I mentioned before?

[adaytay]

I did, yes.

The only things currently connected are a keyboard, monitor and mouse. I've disconnected all the IDE devices and PCI cards that were connected, and although the CPU fan is still going around the power switch has no effect.

I reset the flushed the bios by moving the jumper while the power lead was unplugged as the motherboard must be receiving power in order for the CPU fan to be turning, is that correct?

Thanks,

Ad

[profdlp]

...I reset the flushed the bios by moving the jumper while the power lead was unplugged as the motherboard must be receiving power in order for the CPU fan to be turning, is that correct?...
As long as you removed the CMOS Battery as well that should do it. Some systems seem to take a little while to dissipate the voltage. Try leaving the power cord disconnected, the battery out, and the jumper in the clear position for fifteen minutes.

If none of that works it is either the MB, CPU (highly unlikely), or RAM. Do you have spare memory you could try?

[adaytay]

As long as you removed the CMOS Battery as well that should do it. Some systems seem to take a little while to dissipate the voltage. Try leaving the power cord disconnected, the battery out, and the jumper in the clear position for fifteen minutes.

If none of that works it is either the MB, CPU (highly unlikely), or RAM. Do you have spare memory you could try?

Hi Prof,

Thanks for that, I've done as you suggested (first time I only did it for around 5 mins). Will let you know what that outcome is.

And... I've not got any spare memory of the correct type, no :(

Thanks again for your help :)

Ad

[profdlp]

My guess is that the MB has breathed its last gasp. I would love to be wrong, though.