nandrews said:
Paul,
Thanks for the reply.
I will try and locate the BIOS chip and see which it is, but likely
that it is an Award.
Do you read the 'Repeating (endless loop)' as the same as I described
- long tones with short breaks?
However I have now swapped/rotated/exchanged the two memory cards, so
that each of the two has been in each of the two slots. No change
observed. I can't believe that both have failed at the same time!
Also note, the BIOS tone only occurs very occasionally. Most times at
power-on the fans run and the hard disks 'chatter' for a short while,
but nothing else. The monitor power light stays yellow.
I have swapped out the video card.
My next task is to check the various voltages on the PSU.
But if you have any other thoughts they will be welcome.
Thanks again
Nigel
This PC has developed problems before this point.
In normal mode WinXP would 'BSOD' after an hour or so. But ran in Safe
Mode without any problem.
Sometimes restarting the display would not show, though usually next
boot would be OK.
Then near the 'end' it would boot to just a flashing cursor on a black
screen,
In an effort to deal with the BSOD's I had reinstalled XP, but after
entering the activation key I got a BSOD!
Then it behaved as it does now.
You can get a PCI port 80 POST card, and use that to chart the progress
of the BIOS at startup. It usually has at least a two digit display,
with hex codes from 0x00 to 0xFF. The BIOS writes to port 80 in the
I/O space, on the PCI slot nearest the processor, and using the
little diagnostic display, you can get a code from that. The codes
are "progress" and not "error" codes. On entering a subroutine, the
BIOS writes to the display, and that tells you what subroutine is
running at the moment. The display can update faster than you can follow
it.
(These can vary in price, anywhere from $10 to $100, with the cheapest
coming from Ebay via Hong Kong. These aren't particularly a good investment,
due to the lousy state of documentation on the codes. Many times, a
poster will post a value seen on the card, and the bioscentral.com table
says "reserved" for the value. Which means some BIOS developer, added
their own code number. Still, if you want further help on a startup
problem, this is an option.)
http://www.newegg.com/Product/Product.aspx?Item=N82E16815158065
If you were consistently stuck with a flashing cursor, I might look
for a USB card reader installed on the machine. Sometimes toggling
the USB legacy BIOS setting can help in that case.
If the disk is chattering, and yet the BIOS is not able to detect
it, I don't know what that means in terms of hardware fault. Maybe
the info on the disk wasn't readable, for a particular sector ?
Maybe the disk didn't say "I'm ready" in time, to meet the timeout ?
When is the last time you ran a diagnostic on the hard drive ?
Seagate makes a tool for their disks, which you can run from a
floppy or CD, to verify the disk. As far as I know, that one is
non-destructive. There is a good deal of variation, amongst
the disk brands, as to how much good free software you can
find from their web site, for download.
If it was solely a power supply issue, you'd think you wouldn't
get to use the machine, quite as much as you are currently.
(Failures would be more consistent and more serious.)
I would try booting the machine with something else. A diagnostic
CD might give you a feeling for how well the machine works, with
something other than a hard drive for boot.
A Linux LiveCD is also a good diagnostic tool - it doesn't install
software on the hard drive. If the hardware is unstable, you can
see whether a second operating system like Linux, also thinks there
is something wrong. The only problem with this idea, is finding just
the right distro for the job. My favorite is Knoppix 5.3.1, but that
is DVD sized and too big a download. If I had to choose a good version
other than that one, I guess it would be 5.1.1 CD version. What I look
for, is something that visually resembles Windows, so you'll recognize
at least a few similarities to Windows. Some distros are just too
"foreign" for my tastes, and you have to work hard to do anything
in them. The older Knoppix bootable CDs put plenty of text messages
on the screen during boot, which is part of the value of them.
Some of the most recent ones, tend to hide the text, which makes
them less useful for getting hints on "what's broke".
ftp://csociety-ftp.ecn.purdue.edu/pub/knoppix/
KNOPPIX_V5.1.1CD-2007-01-04-EN.iso 713064 KB 1/4/2007 12:00:00 AM
MD5SUM for the file, is 379e2f9712834c8cef3efa6912f30755 . I burned
mine with Nero (which knows how to convert an ISO download into
a bootable CD). The very first time I did this, I discovered my burner
could only handle a 650MB burn, so it actually cost me a new burner,
to make the CD.
This is what it looks like, before the boot process begins.
You can type any boot time options you need. For example, I
use "knoppix screen=1280x1024" to ensure the display is driven
at native resolution. Without help, Knoppix uses a lower res,
which I hate.
http://billy-oneal.com/forums/ScreenShots/knoppixboot.png
Paul
