PC Wouldn't Shut Off Now Won't Power Up

  • Thread starter Thread starter Lez Pawl
  • Start date Start date
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Lez Pawl

The Browns said:
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
Click to expand...

Ram maybe..............if you have 2 or 3 strips, remove them one at a time
and try restarts.
 
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
 
The Browns said:
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
Click to expand...
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.
 
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
Click to expand...

You didn't tell us enough about the hardware, the rest of
the system, but I would suspect the power supply has failing
capacitors and look there first.
 
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
Click to expand...

One possibility is that the reset button is stuck in the ON
(closed) position. Disconnect the switch from the front panel
connectors header on the motherboard and try to power up
again.

(When I do this kind of thing while trying to isolate a
defect, I usually disconnect the hard disk first).
 
My PC had been refusing to shut off. Now it won't power up.

the system, but I would suspect the power supply has failing
Click to expand...

It was the power supply. I took it to a local shop who tested
it for free (not including the price of the new one they sold me :-))

I had guessed the motherboard which would have meant
finding a socket A MB quickly (nearly impossible) or spending
$400+ on an upgrade.

Thanks to all who responded.

Gary
 
It was the power supply. I took it to a local shop who tested
it for free (not including the price of the new one they sold me :-))

I had guessed the motherboard which would have meant
finding a socket A MB quickly (nearly impossible) or spending
$400+ on an upgrade.

Thanks to all who responded.

Gary
Click to expand...

I hope they sold you a good one - that board uses 5V power
for the CPU vcore subcircuit, meaning for best results
either an ATX 2.0 or older PSU, or a very high capacity and
high quality newer PSU design is needed. Otherwise, it's
likely to have another PSU failure. An honest combined
rating on the 3.3+5V rails of 200W, or more with a lot of
parts like (for it's time) higher end video card, is highly
preferred. A more conservative rating would be 230W+
combined rating for those rails, something even most modern
500W PSU don't provide, but was not uncommon on older
350-400W PSU.
 
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