[Novalug] Dead Computer Diagnosis

[Ben Creitz]

On 11/16/06, David A. Hammond <hammonds at starpower.net> wrote:
> I have a machine which is (nearly) dead and I need some help
> getting started on diagnosing it.  There's not much to go on.
>
> When I hit the power switch, it lights up and both fans (power
> supply and cpu) spin.  Nothing else happens.  The keyboard
> lights don't flash, there's no beep, and no synch is sent to
> the monitor.  As best I can tell there are no diagnostic leds
> anywhere on the motherboard.
>
> What led up to this state is as follows:
>
> This machine is primarily used as a file server, name server,
> DHCP server, etc.  A couple of nights ago it wasn't serving
> anything and I could not ping it, so I turned the monitor on
> and found that I had no synch.  So I tried to reboot it.  It
> got pretty far into the boot sequence (Fedora Core 3) and
> hung.  So I tried again.  It didn't get as far so I tried
> yet again.  This time it quit even quicker, so I figured maybe
> it was a heat problem and unplugged it for about a half an
> hour.  When I powered it back up I went into setup so I could
> watch the cpu temperature.  It started at 36 C and slowly climbed to 45 C where it seemed to level off.  I then turned
> it off but did not unplug it.  When I came back the next
> evening, I found it in the state described at the top of this
> note.
>
> One other thing:  When I was trying the reboots the first
> night, I could power the machine off with the front panel
> switch but I could not power it back up unless I unplugged
> it for about 10-15 seconds.  Does this give any hints?
>
> I have a digital voltmeter, so I can check voltages out of
> the power supply.  I haven't done that yet.
>
> (Please respond to the list or to hammonds at erols.com.  I am
> using webmail from work now, so the From address is probably
> not right.)

Swap in another power supply.  It sounds to me like the current one
(pardon the pun?) may be knocking on death's door.  You can use the
multimeter to test things, but keep in mind that things may change
intermittently.

-Ben