Possible reason computer "shuts off"?

[CaZeek]

I leave my computer on so that Multimedia Center will record some TV programs on a set schedule. However, I've come back several times recently to find that my computer is no longer on. The power isn't going out or anything so it's not that. Ths computer isn't actually off, it's on, but the monitor is no longer on (in power save mode), which leads me to believe it may have returned to the Windows XP sign in screen. I've turned off screen savers completely, as well as hibernate. Are there any other faators that might lead to this?
Thanks!

[thecoalman]

Not sure if you mean it's completely off or restarting spontaneously. If it's the latter that can happen if the CPU is overheating among other things. If it's just returning to the user logon screen got to desktop>right click>proerties>screensaver>power settings> and select never for both standby mode and turn off harddisks.

[CaZeek]

Thanks for the reply.
I'm not exactly sure of what it's doing, as I don't see it while it's happening. The monitor does not display anything when I come back, but the computer is on. However, I'm almost positive that it restarted or otherwise went to the login screen, as it's impossible to get the monitor to display anything, and the tasks it was supposed to perform are not performed. I've already turned off the standby modes, so it's not that. I have no programs running other than the ATI Multimedia Center TV, but if it is overheating is there anyway to check or prevent this?
Thanks again.

[thecoalman]

souds like it's something other than overheating now that I understand the comp is still on but the monitor won't come on....... Has it always done this or is this something new?

[bazooka]

The trifecta

It sounds like an overheating issue.

[CaZeek]

Well I got the ATI AIW card and started capping shows with it (about 3 months ago). In the beginning, I could leave it on for a week and it would still be fine when I got back (everything recorded). Occasionally I'd come back the and it would be "off", and maybe the last day or two would not be recorded. Recently, however, I'll come back later on the same day, at it will be "off", and this is really inconvenient.

[thecoalman]

You can look up your MB manufacturers site, they should have a utility for the temps and fan speeds. May already be one on there. Not sure about ATI but nvidia has the video card temp right in the advanced property display dialog box.

You could also just open the case up and see if the heatsinks on your CPU and Graphics card are packed with dust.

Usually the cpu temps can also be found in the bios setup screen that can be accessed when you first turn your computer on. Should be around 35-45 degrees celcius just sitting there.

[gmatov]

Turn your monitor off then back on to see if it says "Monitor working, check your video cable and PC."

I have had machines go to sleep when I neglected to set sleep mode to Never, and not Wake up with the mouse or KB. Sometimes persistent mousing and keying would work, sometimes needed a reboot.

Annoying.

Cheers,

George