On 19 Sep 2006 06:31:17 -0700,
tofu.captain@gmail.com wrote:
>Months ago one of my main computers running winXP crashed. At first I
>thought it was a software issue, and reinstalled XP. However, the
>video seemed to struggle upon installation.
What _exactly_ does "seemed to struggle" mean?
These are key details and you're leaving them out.
>So I put in a another hard
>drive and installed Ubuntu Linux. It worked fine for a few days and
>then the video on the monitor also begain to freeze and lock up the
>system.
Video freezing means what? Whatever is on screen remained
static? Was there any system activity resulting from mouse
or keyboard input? I don't mean video changing, I mean like
trying to shut down with <Win><U><Enter> or other commands?
Video freezing could be one of many things, like a power
supply problem crashing the system, or motherboard, though
seldom the video card itself (though possible?).
>
>Now, I can't get the computer to POST and the mobo complains about the
>AGP slot.
If it won't POST, how can it be complaining about the AGP
slot?
You need to tell us exactly what you are observing instead
of the summary conclusion.
>
>The problem is that no matter what video card I put in, the video card
>fan will not spin.
.... and at this point, what else is or isn't happening?
My point might be that video doesn't usually freeze because
of the video card, as the video card is still actively
sending that signal to the monitor- if it were not, the
monitor would be blank. Even so, video cards can fail in
different ways, it would be good to try another one.
> So that rules out the problem being the video card.
No, it does not rule out a video card problem, but it does
suggest there might be something else wrong. In other
words, the video card is probably fine but only having it
working, in a runnning system, rules it out.
One possibility at investigating this situation would be to
unplug the video fan, use a multimeter to check the fan
header output (voltage), and trace back that subcircuit to
the AGP connector pins (probably 12V), and with the board
out of the case, measure that connector voltage on the back
of the board. It is not exactly easy to prop up a board,
have it running, and probe these connections though unless
you have a jig set up to suspend a board with the back
exposed, but I mention it because sometimes directly
following a fault backwards you can find where the problem
starts, and it can take creativity in deciding the best way
to do it, ways seldom mentioned as generic PC
troubleshooting tips.
If using a multimeter is beyond your skill level, then what
remains beyond stripping the system down (as mentioned
elsewhere in the thread) is swapping parts- either those
available or by purchasing other parts (preferribly from a
place with a good return/refund policy).
> So my question is, how do I determine if the problem is the
>motherboard or the power supply?
In that non-POSTing, non-running state, use a multimeter to
check PSU voltages.
Unplug the system from AC power for at least 10 minutes, and
pull the battery at the beginning of AC disconnected, or use
the clear CMOS jumper.
If nothing else helps, begin stripping system down to bare
essentials- leaving only CPU, heatsink/fan, 1 memory module,
and video.
At this point it should be noted that you failed to do
something very important- start out your post with a concise
but complete description of all major parts, including the
PSU make, model, wattage, and the exact CPU you used (as
some A7N8X may have a rare problem with mobile bartons- I
still have one of these boards somewhere that only posts
about 1 time out of 12 with a mobile barton, but runs fine
with same barton far overclocked IF it posts, or always
posts with another pre-Thornton Athlon XP.
If you have another video card, particularly an old PCI card
(being more compatible with legacy modes due to PCI, and
also more likely to use less power), disconnect AC power,
pull the AGP card, put in the PCI, clear CMOS, then plug in
AC and try to POST again. Try it at least 2 more times, as
it may reset the bios defaults to the lowest FSB at this
point if it had tried the CPU default previously (I don't
recall on that particular board, if it does this).
>
>Everything else works fine, so that leads me to think the mobo may be
>the problem. But how can I be sure of this?
After exhausting everything you/we/whoever can think of, all
that remains is swapping questionable parts into another
system or known good ones into that system. Do try it with
the stripped-down config mentioned above, first.
If your PSU is generic or not rated for more than 180W on
the 3V+5V rails, then the PSU is another likely suspect.
Your board uses 5V rail for powering the CPU power
subcircuit, so it needs a fairly strong PSU 5V rating, even
moreso if your video card is power hungry but doesn't use
mostly 12V from an aux connector (some do, some don't, you'd
have to web search for your card's specifics if unsure).
>
>My mobo is an Asus A7N8X Deluxe
>
>This computer isn't old old, and I have already bought a new machine
>for my main needs. But I would like to bring this machine back to life
>as it would be good as another extra computer. I don't want to spend a
>lot of time tinkering around trying to fix it if I could spend ~$100 to
>replace the correct part(s).
It shouldn't cost that much, there are still nForce2 boards
in the market for under $50, or an older design ATX 1.2/1.3
PSU for about the same.
If you are ambitious, you could also unplug your PSU from AC
for a few minutes then open and examine it- mostly checking
for failed capacitors, this is after you'd checked it with a
multimeter, since if the voltages aren't ok then it is more
clearly the problem... but further feedback on the issues I
pointed out earlier might help to pinpoint the problem.
Failure to POST: mobo or power supply? 
Linear Mode
