Windows Server - The cat finally died! (AGP Aperture Size was wrong.)

Asked By Robbie Hatley

19-Mar-10 04:35 PM

First of all... wow, no new threads in this group in 6 days?!
That's rather unusual.

Now, to the main topic of this post: As some of you guys and gals
may recall, I have been posting in here every couple weeks for the last
few months about my "COMPUTER KEEPS CRASHING" issue.  To recap, my
Win2K-SP4 system has been crashing roughly once a day for months.
The crash always involves the following symptoms happening
simultaneously:
- usb mouse goes offline (mouse pointer stops responding to it)
- serial mouse does NOT go offline (mouse pointer responds)
- all networks (ethernet, usb, 1384, Internet) go offline
- sound starts cutting in and out about 3 times per second

I have tried many things to fix it, all to no avail.  At times
I thought I'd fixed the problem, only to have it come back
a few days later.  As I put it in one post:

But de cat came back, he could not stay no long-er,
Yes de cat came back de very next day,
De cat came back -- thought she were a goner,
But de cat came back for it would not stay away.

Well, guess what?  I finally killed the damn cat, and the
problem was not even REMOTELY close to any of my previous
guesses, or to any of the advice others gave me.  (No
criticism of folks here implied; the actual cause was so
bizarre that I do not blame anyone for not guessing it.)
The cause?  Incorrect AGP aperture size.

I'd never have guessed that, but for an incident that
occurred about 10 days ago.  I was working along, and
suddenly my screen froze for three seconds (stopped
responding to mouse or keyboard), went black for two
seconds, then returned to normal.  THAT LOOKED VERY
FAMILIAR.  I'd seen that before!  It was a video-mode
reset.  My old CRT monitor used to go "CLINK", go black
for 2 seconds, go "CLANK", then return to normal.  My
new LCD monitor uses solid-state electronics instead of
noisy mechanical relays, so it does not CLINK/CLANK, but
it still goes black for 2 seconds during mode reset.

I seemed to recall having that problem before, so I looked
in my Computer Journal (a text file in which I record
computer maintainance issues from time to time).  Sure
enough, from 2005, I found these entries:

~~~~~~~~~~~~ BEGIN COMPUTER JOURNAL EXCERPT ~~~~~~~~~~~~~~~~~~~

Sun. Jun. 19, 2005:
I have been having some annoying problems lately:

I have been experiencing frequent video-mode resets, especially
while operating scrollbars on windows screens; the monitor goes
normal, except for some scrambled content in windows, and some
bad pixels in window frames, both of which usually (but not
always) will correct themselves on minimize, restore.

Also, sometimes my system just freezes up in the middle of work,
video image frozen, no response from keyboard (CAP-LOCK and
NUM-LOCK buttons will not toggle LEDs), no response from mouse
(pointer is frozen).  I have to press the front-panel "Reset"
button on my machine to un-freeze it.

Tue. Jun. 24, 2005, 4:00AM:
I replaced my video card with a BFG nVidia GeForce MX 4000 128MB
AGP8X.  The instructions were very adamant about several issues:
1. The old drivers MUST be uninstalled before installing new
drivers.
2. The BIOS "AGP Aperature" setting MUST match the number of MB
of RAM on the video card.
3. System BIOS and video BIOS "shadow" or "caching" MUST be
turned OFF.

Sat Aug 27, 2005:
After about 90 days of heavy use, the problems listed above are
completely gone.  I think now that these problems were entirely
due to a bad video card.

~~~~~~~~~~~~ END COMPUTER JOURNAL EXCERPT ~~~~~~~~~~~~~~~~~~~

So it turned out, I'd had both the crash problem and the video mode
reset problem before.  And I'd fixed them, and they'd stayed fixed
for some months.

So, what did I do to fix them?  Four things:

1. Replaced video card.
2. Set "System-BIOS Caching" to "Off" in BIOS settings.
3. Set "Video  RAM  Caching" to "Off" in BIOS settings.
4. Set "AGP Aperture Size" to match video RAM size in BIOS settings.

So what changed, that would cause the malfunctions to resume?

1. Video card?  Still same card, and still seems to be working ok.
2. System BIOS Caching?  Still "Off".
3. Video  RAM  Caching?  Still "Off".
4. AGP Aperture Size = Video RAM size?
Video   RAM  Size = 128MB.

20-Mar-10 10:15 AM

... or you could have edited the quote? :-)

20-Mar-10 08:12 PM

Apparently not.


It did not.  :-(

After working flawlessly for 10 days after I'd decreased my AGP
Aperture size form 256MB to 128MB, on the 11th day, my system
suddenly crashed again.

Same symptoms as always:
- Sound suddenly went silent.
- Mouse pointer  stopped  responding to  USB   Mouse.
- Mouse pointer continued responding to serial Mouse.
- All networks went offline.
(All symptoms happen suddenly and simultaneously, always the same.)


Different video-card manufacturers have different recommendations.
My card says "set AGP Aperture equal to video RAM size".
My mom's card says "set AGP Aperture equal to 1/4 of system RAM size".


Yes, it could eat up too much of the available address space.


The "AGP Aperture Size" information available on the Internet tends to be
vague and/or suspect.  But I now do not think this is where my problem lies,
anyway.

I am thinking now it is drivers or hardware.  Probably hardware.
Probably VIDEO hardware, because lately I have noticed that these crashes
usually happen when I am watching YouTube videos or playing video-intensive
games.

I opened up my computer, blew out all the dust, reconnected one fan
that was not even running, cleaned all heatsinks, removed and cleaned
and reinstalled all circuit boards, and reseated all power-supply
connectors.

I also noticed that 3 electrolytic capacitors on my video card are
bulging at the top (the 3 triangular pressure relief panels are splitting
apart) and they are leaking a brown crumbly substance (electrolyte?).
Not a good sign.

Worse, 3 electrolytic capacitors on my motherboard are also bulging,
splitting, and leaking.

I am now suspecting out-of-spec power supply unit, causing damage to
both MB and video card.

Unless the capacitor damage is due to heat, in which case it could be
that the video-card and MB manufacturers chose capacitors which do not
perform well when exposed to constant 110F temperatures for 7 years.

So really, I need a new case, fans, power supply, MB, and video card.
But I cannot afford any of it.

So now, my approach to the crash issue is:
1. I am increasing ventillation, trying to get temperatures down.
2. I uninstalled and reinstalled all of my motherboard, video-card,
and monitor drivers back to factory originals, in case it is
an updated driver causing the crashes.
3. I re-installed all of the software I uninstalled earlier, because
this is clearly not a software issue.
4. If it keeps crashing, I will just have to live with it until I can
afford to upgrade hardware.

This is becoming increasingly off-topic in this group because I can
see now it is likely not a Windows-2000 issue, so I will stop posting
about this issue in this group, unless future evidence indicates
the OS is involved.

--
Cheers,
Robbie Hatley
lonewolf at well dot com
www dot well dot com slant tilde lonewolf slant

20-Mar-10 08:18 PM

I know it is not supposed to matter these days but in the old days we'd
have suspected an IRQ problem. Have you checked the BIOS settings in
that area .... so that it *is* letting Windows handle the interrupt
settings?

20-Mar-10 09:11 PM

I did check that out.  I set all the IRQs manually in BIOs instead
of letting the PIC (Programmable Interrupt Controller) set them
automatically.

BUT, that is irrelevant, bucause when windows starts up, it turns
the PIC chip *OFF*, and uses the APIC (Advanced Programmable
Interrupt Controller) chip instead.  The APIC remaps all the IRQs.

that everything has a separate IRQ except for the following 7 items,
all of which are sharing IRQ 20:

1. USB Host Controller 1
2. USB Host Controller 2
3. USB 2.0 Host Controller
4. Network Controller
5. Audio Processing Unit
6. Audio Codec Interface
7. IEEE-1394 ("Firewire") Controller

Those are exactly the items that all go off-line instantly
(and *ONLY* those items) when my sytem crashes.

I do not think it is an IRQ issue, though.  I happen to know that
those 7 items are all handled by the same IC on the motherboard,
namely the "Southbridge".  So it makes sense that this chip
would have only one IRQ.

Something is screwing-up the Southbridge.  Voltage, temperature,
drivers, hardware conflict (something jamming the PCI bus), or some
such thing.

Maybe too much heat.  I notice the southbridge heatsink is so hot it
burns my finger when I touch it.  I will leave the computer case's
left cover off for the next fortnight and see if the crashing stops.

I will also keep Windbond's "Hardware Doctor" up and running in the
background from now on.  It monitors voltages and temperatures and
sets off an audio alarm if something gets out of spec.

But in the end, in light of the bulging/leaking capacitors I found
on my video card and MB yesterday, I think now that the problem is
decent job, I will build myself a new machine and put this one out to
pasture.

--
Cheers,
Robbie Hatley
lonewolf at well dot com
www dot well dot com slant tilde lonewolf slant

21-Mar-10 11:49 AM

If you cannot replace the caps yourself, perhaps you could look up a
replacement board for your PC (exact same model) and then you could just
replace that without really installing anything else. You may find it on the
Internet really cheap.
If you buy a different model motherboard, then you may have to install mb
drivers, etc.
Buffalo
PS: Yes, there were a bunch of bad caps being used years ago, even by some
of the big names.