Computer randomly powers down on its own

[Guest]

I am having a problem with my computer which has been causing me quite
the headache. Sorry if this is a bit long, but input or confirmation
of my suspicions would be greatly appreciated.

Initially my computer would shut itself down at what seemed to be a
totally random time. At first it would only happen with graphically
heavy applications such as games. From there it started to do so more
frequently at other times. Now it will do it almost every time Windows
(XP Home) begins starting up. I have noticed it will usually do so now
when either my hard drive or CD drive starts to spin up.

Now the kicker to this issue is the fact that once it does shut down,
the only way to power it back up is by either unplugging my computer,
turning off the UPS it is connected to, or by flipping the switch on
the computer's power supply from off to on. If I don't do this, it
will not even react to the pressing of my power button.

Additionally I noticed prior to this that my power supply seemed to be
getting excessively hot. And as one more side note, the computer
seemed to have more problems when I had more components plugged in.
Now, the only things connected to the power supply are my motherboard,
video card, and hard drive. Sometimes it will get far enough to let me
actually do something, but will eventually shut down again.

It seems to me that everything is pointing to my power supply (400w
ATX) going bad. Does this seem to be a correct assumption or could
there possibly be another culprit?

Thanks in advance for any help.

[Jeremy Boden]

In message <1118258104.981087.130820@z14g2000cwz.googlegroups.com>,
matt.b.williams@gmail.com writesI am having a problem with my computer which has been causing me quitethe headache. Sorry if this is a bit long, but input or confirmationof my suspicions would be greatly appreciated.Initially my computer would shut itself down at what seemed to be atotally random time. At first it would only happen with graphicallyheavy applications such as games. From there it started to do so morefrequently at other times. Now it will do it almost every time Windows(XP Home) begins starting up. I have noticed it will usually do so nowwhen either my hard drive or CD drive starts to spin up.Now the kicker to this issue is the fact that once it does shut down,the only way to power it back up is by either unplugging my computer,turning off the UPS it is connected to, or by flipping the switch onthe computer's power supply from off to on. If I don't do this, itwill not even react to the pressing of my power button.Additionally I noticed prior to this that my power supply seemed to begetting excessively hot. And as one more side note, the computerseemed to have more problems when I had more components plugged in.Now, the only things connected to the power supply are my motherboard,video card, and hard drive. Sometimes it will get far enough to let meactually do something, but will eventually shut down again.It seems to me that everything is pointing to my power supply (400wATX) going bad. Does this seem to be a correct assumption or couldthere possibly be another culprit?Thanks in advance for any help.
It's (just) possible that it could be due to a fault in the UPS. Try
bypassing it to see if it makes any difference at all.

--
Jeremy Boden

[Guest]

Thanks for the input. I'll give it a whirl.

[Guest]

Well, I gave it a try without the UPS but I'm still getting the same
problem. If there are any more suggestions it would be greatly
appreciated.

[Charles Howse]

Previously matt.b.williams@gmail.com wrote: I am having a problem with my computer which has been causing me quite the headache. Sorry if this is a bit long, but input or confirmation of my suspicions would be greatly appreciated.
Initially my computer would shut itself down at what seemed to be a totally random time. At first it would only happen with graphically heavy applications such as games. From there it started to do so more frequently at other times. Now it will do it almost every time Windows (XP Home) begins starting up. I have noticed it will usually do so now when either my hard drive or CD drive starts to spin up.
Now the kicker to this issue is the fact that once it does shut down, the only way to power it back up is by either unplugging my computer, turning off the UPS it is connected to, or by flipping the switch on the computer's power supply from off to on. If I don't do this, it will not even react to the pressing of my power button.
Additionally I noticed prior to this that my power supply seemed to be getting excessively hot. And as one more side note, the computer seemed to have more problems when I had more components plugged in. Now, the only things connected to the power supply are my motherboard, video card, and hard drive. Sometimes it will get far enough to let me actually do something, but will eventually shut down again.
It seems to me that everything is pointing to my power supply (400w ATX) going bad. Does this seem to be a correct assumption or could there possibly be another culprit?
Thanks in advance for any help.

Most likely candidate is the PSU. It seems to get overloaded.
There is a (much smaller IMO) possibility that the power circuitry
on the mainboard is fried. However that would normally not cause
the refusal to start-up, so it woul have to be something relatively
complicated. For the PSU it is simple: It gets overloaded (e.g. due
to capacity loss in the capacitors or because 400W is to small
for your system, depends on CPU, VGA card and other hardware) and
shuts down. Overload protection should shut down the PSU completely,
usually including the 5V aux-power that powert the power-up button and
circuitry. It then needs to be without power to reset.
You can check this: Network cards usually stay powerd during
power-down and their LEDs keep signalling link (on) and
packets (blinking). If power goes asway completely during your
outages the LEDs on the (connected!) network card would go
off as well.

Arno

[Guest]

Thanks Arno, that makes a lot of sense. I'm unable to check at the
moment whether or not the network card's light shuts off when it powers
down, but if I remember correctly (which doesn't happen often) I
believe they do. I will, however, check that out.
As of tomorrow I will be able to test it out with a different power
supply and will report back with the results.

[w_tom]

UPS connects computer directly to AC mains when not in
battery backup mode. Typical UPS would do nothing to cause
your problem - if it works properly.

Step one to solving this problem is getting the facts. One
need not wildly replace things. What does the Device Manager
report? What does the system (event) log report since
failures are something preceded by events only recorded and
bypassed by the OS? Both can be found using Windows help.

What does the manufacturer's comprehensive diagnostics
report - either located in a separate partition on the disk or
downloaded from his web site. If your manufacturer was not so
responsible, then you must download diagnostics from each
component manufacturer.

XP makes hardware problems less problematic. It reduced the
number of suspects that can crash a system. Those suspects
include sound card, memory, and video controller. What do
those diagnostics report?

The, of course, there is the foundation for all computers -
the power supply system. That 'system' is more than just a
power supply. And we confirm the 'system' integrity in but
less than two minutes with a 3.5 digit multimeter. A tool so
ubiquitous as to be sold in Home Depot, Walmart, Sears, and
Lowes. General procedures described previously in
"Computer doesnt start at all" in alt.comp.hardware on 10
Jan 2004 at
http://tinyurl.com/2t69q and
"I think my power supply is dead" in alt.comp.hardware on 5
Feb 2004 at
http://tinyurl.com/yvbw9

In particular, your attention to numbers for the purple,
green, and gray wires - before and when power switch is
pressed - should have your most attention. Without numbers,
all we can do is wildly speculate. Even Motherboard monitor
is not sufficient to obtain these important numbers.

Only once we have confirmed hardware integrity, are we ready
to move on to other suspects inside Windows. Notice the step
by step response to confirm each sub-system one at a time.
Once confirmed, we then move on to other 'usual' suspects. No
wild guessing about 'try this and try that'.


matt.b.williams@gmail.com wrote: Well, I gave it a try without the UPS but I'm still getting the same problem. If there are any more suggestions it would be greatly appreciated.