It just shuts down!?

Info:

CPU and RAM are clean and seated. Power supply is new - thought that was
the problem 4 weeks ago :( Motherboard is an ASUS K8N, 1GB Kingston RAM
and using Debian Etch 32-bit OS; kernel 2.6.18-4-686. CPU is an AMD
Sempron Processor 3000+ - it's a few years old.

Symptoms:

Seen this problem sporadically over the last month where the computer
becomes suddenly unresponsive. The LCD monitor goes black. Viewing the
CPU fan and power fan shows they're ON and the fairly new SATA hard
drive makes an occasional small 'click' noise. The monitor looses its
signal. Nothing to do but press the Power button for 3 seconds which
actually shuts down the machine. Upon a reboot, following the 'post' but
before GRUB, a small curse-like line is on the upper top left of the
monitor. After 2-3 seconds GRUB begins and the system behaves normally
for an unspecified time.

Here are some logs from this most current event just before and
afterwords (from stoppage to restart):

_syslog_

Apr  1 23:47:16 sk8r gconfd (cody-4122): Exiting

Apr  1 23:47:23 sk8r kernel: NVRM: Xid (0001:00): 16, Head 00000000
Count 0000b117
Apr  1 23:51:05 sk8r shutdown[4291]: shutting down for system halt
Apr  1 23:51:05 sk8r init: Switching to runlevel: 0
Apr  1 23:51:06 sk8r gdm[3071]: mainloop_sig_callback: Got signal 15
Apr  1 23:51:06 sk8r gdm[3071]: mainloop_sig_callback: Got TERM/INT. Going
down!
Apr  1 23:51:06 sk8r gdm[3071]: gdm_final_cleanup
Apr  1 23:51:06 sk8r gdm[3071]: gdm_display_unmanage: Stopping :0 (slave
pid: 3077)
Apr  1 23:51:06 sk8r gdm[3077]: Sending SESSPID == 0 for slave 3077
Apr  1 23:51:06 sk8r gdm[3077]: gdm_slave_session_stop: cmo on :0
Apr  1 23:51:06 sk8r gconfd (cmo-3279): Received signal 15, shutting
down cleanly
Apr  1 23:51:06 sk8r gconfd (cmo-3279): Exiting
Apr  1 23:51:09 sk8r shutdown[4306]: shutting down for system halt
Apr  1 23:52:02 sk8r syslogd 1.4.1#18: restart.

_user.log_

Apr  1 23:47:16 sk8r gconfd (cody-4122): Exiting
Apr  1 23:51:05 sk8r shutdown[4291]: shutting down for system halt
Apr  1 23:51:06 sk8r gconfd (cmo-3279): Received signal 15, shutting
down cleanly
Apr  1 23:51:06 sk8r gconfd (cmo-3279): Exiting
Apr  1 23:51:09 sk8r shutdown[4306]: shutting down for system halt
Apr  1 23:52:03 sk8r hpiod: 1.6.10 accepting connections at 2208... 
Apr  1 23:52:09 sk8r dhcdbd: Started up.

_messages_

Apr  1 23:47:16 sk8r gconfd (cody-4122): Exiting
Apr  1 23:51:05 sk8r shutdown[4291]: shutting down for system halt
Apr  1 23:51:06 sk8r gconfd (cmo-3279): Exiting
Apr  1 23:51:09 sk8r shutdown[4306]: shutting down for system halt
Apr  1 23:52:02 sk8r syslogd 1.4.1#18: restart.

Query:

Anyone know what's wrong or can suggest a means to discover the cause?

Thank you!,
-- 
sk8r-365
And his disciples asked him, saying, Why then say the scribes that

Thus spake sk8r-365:
<snip>
> Apr  1 23:47:23 sk8r kernel: NVRM: Xid (0001:00): 16, Head 00000000
> Count 0000b117
<snip>

BTW, I think it may be an nVidia issue, but frankly haven't enough
background in such matters. Therefore, I'm seeking the advice of other
more experienced users.

Again, thank you.
-- 
sk8r-365
And he saith unto him, Friend, how camest thou in hither not having

"sk8r-365" <sk8r-365@sk8r.debian.etch.invalid.org> wrote in
message 
news:GPidndeiVuXhuG7anZ2dnUVZ_vGinZ2d@bresnan.com...
> Info:
>
> CPU and RAM are clean and seated. Power supply is new - thought that was
> the problem 4 weeks ago :( Motherboard is an ASUS K8N, 1GB Kingston RAM
> and using Debian Etch 32-bit OS; kernel 2.6.18-4-686. CPU is an AMD
> Sempron Processor 3000+ - it's a few years old.
>
> Symptoms:
>
> Seen this problem sporadically over the last month where the computer
> becomes suddenly unresponsive. The LCD monitor goes black. Viewing the
> CPU fan and power fan shows they're ON and the fairly new SATA hard
> drive makes an occasional small 'click' noise. The monitor looses its
> signal. Nothing to do but press the Power button for 3 seconds which
> actually shuts down the machine. Upon a reboot, following the 'post' but
> before GRUB, a small curse-like line is on the upper top left of the
> monitor. After 2-3 seconds GRUB begins and the system behaves normally
> for an unspecified time.

You are in the wrong group.. the vista group is ---------> 

Thus spake dennis@home:
>
> From: "dennis@home" <dennis@killspam.kicks-ass.net>
> Newsgroups: alt.os.linux
> Subject: Re: It just shuts down!?
> X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606
> X-Antivirus-Status: Clean
> X-Newsreader: Microsoft Windows Live Mail 12.0.1606
> Importance: Normal
> X-MSMail-Priority: Normal
> Bytes: 2376
>
>
> "sk8r-365" <sk8r-365@sk8r.debian.etch.invalid.org> wrote: 
>>
>>> Info:
>>
>> CPU and RAM are clean and seated. Power supply is new - thought that
was
>> the problem 4 weeks ago :( Motherboard is an ASUS K8N, 1GB Kingston
RAM
>> and using Debian Etch 32-bit OS; kernel 2.6.18-4-686. CPU is an AMD
>> Sempron Processor 3000+ - it's a few years old.
>>
<snip>
>
> You are in the wrong group.. the vista group is ---------> 
>

Wow Dennis; such searing logic.

Folks, I see we've found the one in our crowd.

-- 
sk8r-365
But when ye pray, use not vain repetitions, as the heathen do: for
they think that they shall be heard for their much speaking.

Thus spake Man-wai Chang ToDie:
>> and using Debian Etch 32-bit OS; kernel 2.6.18-4-686. CPU is an AMD
>> Sempron Processor 3000+ - it's a few years old.
>
> You wanna try Ubuntu-7.10 or Fedora 8? Debian... um....
>

How does that pertain?

-- 
sk8r-365
And again he denied with an oath, I do not know the man.