"The Browns" <garyjbrown@charter.net> wrote in message
news:ruZJh.343$WE4.306@newsfe05.lga...
> Hi,
>
> My PC had been refusing to shut off. Now it won't power up.
> Can someone suggest a possible cause? Motherboard? Power
> supply?
>
> The past four times I tried to shut down my PC it wouldn't turn
> off. Holding the power button produced a click, a drop in power
> (noise) for about half a second then it would start to power up
> again. Pulling the plug or turning off the UPS was the only way
> to shut it off.
>
> This morning it refused to power up. It gets so far then appears to
> be doing a reset. It doesn't get far enough to get into the BIOS.
>
> I unplugged the Disk and CD/DVD drives to reduce load (and
> protect them), then reseated power and power control connectors.
> Those had no effect.
>
> The PC is homebuilt with an ASUS A7N8X Deluxe MB, about
> 3 1/2 years old, the PS is an Antec SmartPower 350, maybe a year
> old. The box is generic.
>
> Any help appreciated.
>
> Thanks,
> Gary
>
>
With the initial symptom of not being able to shut down the machine using
the power button and now it no longer powers on might indicate that the
power button itself is defective.

It's easily tested by unplugging the cable going to the power button at the
motherboard and momentarily shorting the same pins on the motherboard and
see if the unit powers back on.

From there the list of causes can grow quickly, from power supply,
motherboard, memory, etc.