What could cause a PC to turn it self off

[Meat Sauce]

Both my father's and my pc suddenly cut power every now and then. It doesn't
go through shutdown, it just powers down like someone cut the power cord or
pulled it out. After it shuts down I have to cycle the rocker switch on the
power supply to get the computer to boot. I have ruled out the UPS as they
are both APC models and mine is a Back UPS 1400 ($600 model) and power is
still going to the monitor through all this. It would be highly unlikely
that both our UPSs are faulty. I have vacuumed out my Father's PC and this
morning it exhibited the same behavior.
Do I need to blow out the power supply too? There is not much dust buildup
inside the cases. The power supplies in the two PCs are Fortrons. Could it
be a faulty power supply? Or could it just be heat? I have checked the temp
range in BIOS and it was about 20 C when one shut down while in the BIOS
setup. The room temps are in the lower 70 F range.
What else could be causing the random shutdowns?
Thanks for any help in advance.

 

[Guest]

Use process of elimination connect the pc direct without
the ups and if it exibits that problem u have ruled out ur
ups. Now you know that it can be a power supply issue and
u can get one from a know working pc replace the current
one run a test.

 

[scottie]

first, it is possible to reboot or shutdown through
software, so observe what programs are running when the
shutdown occurs to eliminate that factor.

what is strange is that both units have this ugly
behavior. that means that if the problem is not your
software application, it is a manufacturing defect,
possibly firmware, powersupply, or motherboard, so if
you're in warranty, go that way.

you can look on the manufacturer's website for known
issues. often, firmware upgrades can be downloaded even
if out of warranty at no charge.

if you are out of warranty, you can open the case to
determine if the problem is a cpu overheating issue.
place a fan, perhaps a floor model to get a good stream of
air over the cpu -- the cpu as it has a heat sink (metal
bladed unit to disipate heat) on it, and usually a mini-
fan over that. ensure that the unit is on a non-
conducting material such as cardboard, glass, or a wooden
tabletop then power up. do not touch the inside of the
box to prevent shocks, burns, or pc damage. run that way
for a long while to see if it is an overheating issue. if
there's no power interruptions, it likely is and perhaps
an additional/better fan is all that is needed.

if not a cpu overheating problem, it may be an inadequate
power supply. a good p/s is 35 or 40 watts minimum.
check the label on the unit. you can buy replacements but
make sure the unit will fit in your system before buying.
if you go that way, just buy one, test it for a few days
and if it solves the problem, buy another for the other pc.

good luck and happy holidays!
scottie

 

[CWatters]

Two computers with similar problems - sounds like a virus? Could it be the
RPC virus?

 

[Ken Blake]

In

Two computers with similar problems - sounds like a virus? Could it
be the RPC virus?

If, by "the RPC virus," you mean the worm called Blaster or
Lovesan, the symptoms don't sound at all like it.

 

[Meat Sauce]

I've checked mine for a virus and Symantec found nothing. My Dad's comp
won't stay up long enough to scan for viruses.
I plugged it (Father's PC) directly into a wall outlet and same thing,
barely got through a hard drive check and then shut down.
Could it be that the motherboard is not sensing the cpu temp correctly?
I'm going to take the PS out of this PC (it's been running fine for over a
week) and stick it in the other now.
Keep your fingers crossed.

 

[Jim Macklin]

It could be a power surge, you might have your power company
put a recording monitor on the line.


| I've checked mine for a virus and Symantec found nothing.
My Dad's comp
| won't stay up long enough to scan for viruses.
| I plugged it (Father's PC) directly into a wall outlet and
same thing,
| barely got through a hard drive check and then shut down.
| Could it be that the motherboard is not sensing the cpu
temp correctly?
| I'm going to take the PS out of this PC (it's been running
fine for over a
| week) and stick it in the other now.
| Keep your fingers crossed.
|
| | > Two computers with similar problems - sounds like a
virus? Could it be the
| > RPC virus?
| >
| > | > > Both my father's and my pc suddenly cut power every
now and then. It
| > doesn't
| > > go through shutdown, it just powers down like someone
cut the power cord
| > or
| > > pulled it out. After it shuts down I have to cycle the
rocker switch on
| > the
| > > power supply to get the computer to boot. I have ruled
out the UPS as
| they
| > > are both APC models and mine is a Back UPS 1400 ($600
model) and power
| is
| > > still going to the monitor through all this. It would
be highly unlikely
| > > that both our UPSs are faulty. I have vacuumed out my
Father's PC and
| this
| > > morning it exhibited the same behavior.
| > > Do I need to blow out the power supply too? There is
not much dust
| buildup
| > > inside the cases. The power supplies in the two PCs
are Fortrons. Could
| it
| > > be a faulty power supply? Or could it just be heat? I
have checked the
| > temp
| > > range in BIOS and it was about 20 C when one shut down
while in the BIOS
| > > setup. The room temps are in the lower 70 F range.
| > > What else could be causing the random shutdowns?
| > > Thanks for any help in advance.
| > >
| > >
| >
| >
|
|

 

[Meat Sauce]

It was the power supply. My Dad's PC ran for hours on my PS with no
shutdowns. Ordered a new one from Newegg.
Thanks for all your help guys!