HELP! My system won't stay up more than 4 hours!

[Jay "you ignorant splut!" Maynard]

For a while, my system was averaging 18 hours uptime. I went to System
V/AT version 2.4 a few weeks ago, and that helped, for a while: it would
stay up for a week or so - until last Wednesday.

Now, it averages 4 hours uptime, with the longest stretch being 21
hours. This is offset, though, by a large number of crashes while the
system is executing the scripts in /etc/rc.d, before a login prompt is
presented. The crashes are either the dreaded double panic, or a general
protection panic. I'm about to panic.

I can't seem to find a common thread between the circumstances of all
the crashes; the ones that occur after the system is booted seem to
happen as the system is fairly heavily loaded, but that doesn't explain
the ones while booting. In particular, they're not consistently related
to serial port activity, and not at all related to floppy use. I get no
messages prior to the crash, though there is sometimes a pause of a
couple of seconds with no activity at all.

The sudden onset of the problem seems to suggest hardware trouble. The
only diagnostics I have are the standard IBM AT Advanced Diagnostics
suite; the system passes them with flying colors, even when I've let
them run for a full day at a time.

I'm at the end of my rope, and getting damned tired of running five
fscks off of the boot floppy every crash. Anyone out there have ideas?
Software is a stock System V/AT, with standard B news (2.11.14) and a
fair-sized stack of software off the net. Hardware is an Everex/AT Plus
System 1800A (10 MHz, 1 wait state), with 4 MB of 120 ns RAM, 2 serial
ports (1 in active use, with a Courier 2400), 1 parallel port with Epson
FX-185 printer, Video 7 VEGA Deluxe EGA-compatible, Sony Multiscan
monitor, Mouse Systems bus mouse, Central Point Software CopyIIPC Option
Board, two hard disks (Maxtor 1120 as drive 0, and Seagate ST251 as
drive 1), two floppy disks (one 1.2 and one 360), and an unused
monochrome display adapter. BIOS is the stock Access Methods, Inc. ROM,
version A. The system is about two years old.

Please E-mail me; if I fire off an inews -U to clear out the news
backlog, things go to hell in a hurry...

-- 
Jay Maynard, EMT-P, K5ZC, PP-ASEL   | Never ascribe to malice that which can
uucp:        uunet!nuchat!   (eieio)| adequately be explained by stupidity.
    hoptoad!academ!uhnix1!splut!jay +----------------------------------------
{killer,bellcore}!texbell!          | "Less great!" "Tastes filling!"