Re: Computer won't boot -- no error message

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"Natter91" <Natter91@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:A09E7392-8806-441B-A5D4-EA5EF97357EC@xxxxxxxxxxxxxxxx
My computer was working normally until it just turned off. Now, when I
press the power button, the computer will turn on, but it won't start
up. The
monitor is blank and on standby, like it is when it isn't getting
anything
from the computer.

The light on the motherboard is on. All of the fans are working,
including
the one on the video card. Nothing that is attached by USB gets power,
except for a brief flash right when I turn it on. My keyboard, which
is PS/2,
doesn't turn on either.

I did try changing the RAM, but that didn't work. I also tried
switching
the monitor on a suggestion from someone else, but that didn't change
anything either.

My hardware that I can remember:
Motherboard: Asus P4C800-E Deluxe
CPU: Pentium IV 3.2 GHz
Video Card: Ati Radeon 9600 Pro

Thanks!


Anna wrote:
Natter91:
Do this...

1. After powering off the machine and removing the A/C cord from the
wall
socket...

2. Disconnect the HDD from the system; ditto for any optical drive(s),
floppy drive, and any other storage devices, printer, etc.

3. Work with only the power supply connected, your RAM, your video card
&
monitor, (you can leave your mouse/keyboard connected), but nothing
else.
No other peripherals, OK?

4. Power on the machine.

What happens? Do you get any kind of screen display at all or just a
black screen?

If you do get a screen display can you access the BIOS and manipulate
through the settings there for a period of time? Any problems at this
point?

And the CPU fan is going, right?

If you are able to access the BIOS, check the temperatures shown in the
BIOS display. Any problem here?

If still "dead in the water" it's most likely the processor or the
motherboard; usually the latter.
Conceivably it could be a defective PS even though you're apparently
getting power to the system.

The problem here is that the only way you can definitively tell what's
causing the problem is by substituting components, usually not a
practical
thing for the average user.
Anna


"Bill in Co." <not_really_here@xxxxxxxxxxxxx> wrote in message
news:%23e3GkNFuIHA.1768@xxxxxxxxxxxxxxxxxxxxxxx
If he is able to access the BIOS, that indicates the CPU is functioning,
at least to that level, obviously. But I am curious to know how many
CPUs could do that (allowing access to BIOS means the CPU is
functioning) but still be defective beyond that in practice. But I
haven't >>> seen enough data to really know.


Anna wrote:
Accessing the BIOS in & of itself does *not* exclude the possibility of a
defective CPU.


"Bill in Co."
True enough.


Anna wrote:
We've encountered a number of instances where we were dealing
with a defective processor under those circumstances.


"Bill in Co." wrote...
That's what I wanted to know! - Thanks. So you've actually had cases of
such CPU failures in practice? Which is interesting to know. I knew
(as an EE) it was theoretically possible, but I wanted to know if it
really happens, in practice. So thanks for that update.


Anna wrote:
As you may have noted
I suggested that should the user be able to access the BIOS he or she
should
remain in that area "for a period of time". It's one of the diagnostic
procedures (admittedly somewhat crude, but possibly useful for end-users)
we've used in these situations that sometimes will expose or at least
give
some indication of a defective processor in that a black screen will
return during this time. Anyway, it's useful to check CPU temperature
while >> in the BIOS.

As I've indicated, (again, based on my experience), if it is a hardware
failure (the system is "dead in the water"), in most cases it's the
motherboard rather than the processor. But, again, that's not definitive
by any means. And the problem is as I've indicated in my last paragraph
of >> my response to the OP.
Anna


Bill:
Let me add this further comment based on my experience diagnosing &
repairing PCs over the years - particularly with reference to the past
half-dozen years or so...

Assuming that we're dealing with a hardware problem involving a defective
major component, and,
further assuming that the problem arose at some point *after* the system was
working properly, i.e., this is not a new, untried system...

And further assuming that the problem is *not* with the hard drive(s) nor
optical drive(s) - (the usual culprits involving major component
failures)...

(In most cases) it will come down to whether it's the power supply; or the
processor; or the RAM; possibly the graphics/video card, or the motherboard.

The problem for the end-user is that the only definitive way to determine
the problem component is through substitution - obviously not a practical
approach for most end-users.

There are relatively inexpensive (about $20 or so) power supply testers on
the market and they yield surprisingly good diagnostic results, especially
when they find the PS is defective. But again, the only definitive way to
tell is through substitution.

When it comes to the processor and RAM - in comparison to the
motherboard -those components hold up quite well. I might even say that a
defective processor and even defective RAM is a rare occurrence. With
respect to the graphics/video card in most cases where there is a problem
it's because the card isn't properly seated or properly connected.

Again, I hasten to add that all this is with reference to a system that has
been working just fine up to the hardware problem manifesting itself and
obviously no outside physical type problem, e.g., power surges, brownouts,
manhandling the PC, etc., has occurred that might be a source of the
problem.

So that leaves us with motherboards. And in comparison with the other major
components we've mentioned (excepting the drives of course), motherboards
are more frequently the problem.

I'm sure your (and others) will understand that all the above are
generalizations (some might even say "gross generalizations"!). But that has
been my experience over the years.
Anna


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