I recently had a hard lockup on my K8 system (running SuSe Linux) after
over a year of uptime. More alarming than the lockup, the system
wouldn't boot up afterward. During the boot sequence, the graphics card
does its initialization, showing the amount of video RAM, then the
"quick" memory check executes, showing the total amount of RAM, the CPU
ID is printed, and then the system went off into space. No error
indications, no attempt to access any disk or boot up, and no beep error
codes. Keyboard completely unresponsive. The worst part of this was
that it didn't even register my <DEL> key to enter the BIOS setup. It
locked up too soon before that point. So I couldn't see if there was a
temperature/voltage issue from the diagnostics or anything.
I have the "DLink" connector hooked up to the USB internally, which is a
set of LEDs that indicate the current process that is occurring during
boot-up. The LEDs indicated that it was in the process of probing the
PCI bus and scanning for devices.
So naturally my next step is to rip out everything from the system that
isn't glued in. During this process, I happened to notice that one of
the fans bolted on to the nForce4 chip on the motherboard wasn't
spinning. That probably explains why my gigabit ethernet port was
working intermittently at best, and probably explains the lockup (which
occurred just as the temperature shifted here from mid 60's to mid 80's).
So I left the whole system off for a while and let it cool down. I also
finished detaching every device from it, and plugged in a PS2 keyboard
in a final desperate attempt to get into the BIOS. When I powered it
back up this time, it booted, all the way, and seemed stable. I ran it
for a while, then shut it down and started putting pieces back in.
To shorten the story a bit, I discovered that my USB-sharing device is
what was actually preventing my system from booting! I have a KVM
device called an "AirLink 101" which is a 4-port switch for sharing USB
devices, VGA output, and also left & right audio speaker output among 4
machines. It's a generally very nice piece of equipment with 2
exceptions: it doesn't have its own power supply and my laptop's USB
power is just barely enough to keep it alive and working (goes out
intermittently when my laptop is selected), and my Award BIOS is just
completely baffled when I try to boot up with it plugged in to my USB to
the point where it crashes without so much as an error message. Sure
enough, I unplug the KVM switcher and plug the USB devices directly into
the machine, it boots like a champ. It had been so long since I
rebooted the box that I didn't have the switcher the last time, so I
never suspected the switcher as being the problem (especially after
finding the fan stopped).
I'm still concerned about the fan, but I do have excellent cooling
inside of my case and there are two other fans which can function to
cool that area of the motherboard, running full time. I tried detaching
the fan from the chip, but I couldn't. The screw heads were too small
and too tight that I would have to strip them to get them out. I've
been living with it for a couple of weeks now and it hasn't locked since
that day, so I guess I'll take whatever borrowed time I can. ;-)
But I just wanted to put this story out there for anyone else with a KVM
switch in case they develop some hard to explain booting problems at
some future time.
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