Bill said:
Hi,
Working on a Dell Dimension 4400 for the last week running XP
Home...original complaint was blue screen restarts.
So far this is what I've tried:
Switched PSU w/ known good unit...no difference.
Swapped AGP video card w/ known good card...video is clearer, but
still get blue screen stop error: 0X00000000A
Sometimes memtest86 passes all tests, but after a blue screen restart
errors are reported and CPU0 is halted.
Swapped out memory w/ known good sticks...no difference.
Once problems start unit will not boot until it is left for a time.
I suspect a CPU or motherboard problem. Please give me your opinion.
TIA
Bill
According to this, it has diagnostic lights.
http://support.dell.com/support/edocs/systems/dim4400/tour.htm#1101572
When it won't boot, check the lights and see what code is showing.
The codes are listed here. The LEDs are bi-color, there are four
of them, so plenty of combinations (although not all combinations
are used). The table has about eleven codes.
http://support.dell.com/support/edocs/systems/dim4400/codes.htm#1101572
I'd start by simplifying the system. Unplug excess hard drives. If
two sticks of RAM are present, try one at a time. Remove all PCI
cards. Add them back, as the need arises.
I have a couple test cards here. I have an AGP FX5200 video card.
I also bought a PCI FX5200 video card (which I use when flashing
the BIOS on AGP cards). I'd unplug the AGP video, and give a
PCI one a try, just because I happen to have the card. That might
tell you if the AGP interface was a contributing factor.
Examine the motherboard for leaking capacitors. I see a
bunch, just below the white S478 socket here. Leaking caps
wouldn't account for your symptoms, but they can give you
an excuse to toss the system.
http://i10.ebayimg.com/07/i/000/fb/df/9cdc_1.JPG
I don't know what the chipset is. If it was an 865PE
board, with an ICH5/ICH5R Southbridge, the Southbridge
is prone to USB failures (latchup, ESD related). But
that wouldn't account for your symptoms either. Symptoms
there would be a loss of all USB ports, or a permanent
failure to POST.
The blue screen might be due to something overheating.
The processor probably has THERMTRIP, so it can protect
itself and turn off the computer (so that is not the problem).
When other things overheat in the computer, they cannot protect
themselves. Then you might see a crash. They'd probably cool rapidly,
so it shouldn't take long before they can run again. Sometimes,
if they use wire loops to hold a heatsink down, the solder
comes loose on a plug holding the wire loop in place,
and a wire loop falls off.
Some motherboards have a sort of "cold bug", where you
can apply power, and it takes Forever before they start.
Motherboards have extensive "power good" logic for startup,
which controls the sequencing of the startup. In one
case, monitor leakage flowing down the monitor cable,
contributes to a long interval before the motherboard
realizes it is coming out of reset (unplug monitor and
see if it starts faster). It is pretty hard
to guess exactly where, and what fault that is. You
don't fix stuff like that (unless you can get a schematic,
and, you can figure out what they're doing).
You can also try an alternate OS. I use Knoppix (a Linux
LiveCD), and watch the boot sequence, to get some hint about
what is wrong. I can run Prime95 under Linux, just as easily
as under Windows. In the case of my first computer, I
discovered both OSes showed the same flaky video operation,
and there is a design flaw in that board when more than
512MB of RAM is installed. That is an old P3 system.
Before I tried Linux, I wasn't really sure what was going
on, but seeing Linux crash while the desktop was idle,
told me it was hardware. (The best version of Knoppix, would
be before the current 6.0 release. 5.3.1 is a DVD, so isn't
good for older systems that only have CD drives. The releases
before 6.0, print lots of text on the screen during bootup,
which is a "feature". So something before 5.3.1, CD sized, might
be something to try. The release list is at the bottom
of the page here.)
http://en.wikipedia.org/wiki/Knoppix
(Screenshot during boot)
http://frrl.files.wordpress.com/2008/10/knoppix_boot.jpg
Linux doesn't work a video card very hard. (Compiz is as
close as they get, to working the card, and it is available
in the latest releases. Perhaps 5.3.1 or later.) If Linux
stays up, and Windows crashes, it might be video related,
and Linux isn't kicking the video hard enough. I've run
Quake3 Arena under Linux, and if I needed a gaming environment,
that is all I've got here to test with. The map files
for that, come from a Mac version of the game
ID software has a Linux executable for download, as
long as you have the map files.
You asked whether it is CPU or motherboard, and
I've have to answer it is a motherboard problem.
CPUs generally don't fail (unless a "mad scientist"
has been inside the computer). Since processors
after the early Athlons are thermally protected,
there is less that can go wrong now. Both
AMD and Intel are protected now.
HTH,
Paul
