Computer Boots, Then Monitors Shut Off

July 2, 2006 2:47 PM

My computer boots, but the monitors go black before the OS loads.

I restarted my computer this afternoon because I'd heard a sound [something like the whining noise of a chopsaw, heard from far away] coming from my computer, and I couldn't figure out where it was coming from. I'd heard this noise occasionally in the past, but restarting the computer after a short break generally eliminated the problem. [My suspicion has generally been that this may have something to do with fans and overheating, since my computer's always on, but I've never really investigated it further.]

This time, however, the computer went through the boot process, but the monitors went black before the Windows login screen appeared. I tried to go through the login process blind to change the display settings, but [though the computer appeared to be on, and all fans were running] there was no effect. Restarting the computer with only one monitor plugged in results in the same problem. Windows does start in safe mode, and it doesn't seem to me that the boot drive [or any of my other hard drives] is malfunctioning - nor apparently are either of the monitors, although in safe mode, the normal dual-monitor setup doesn't work. Nothing strange seems to be showing up in the event viewer [except for the notes about processes not running in safe mode], and the computer is not making any further unusual noises.

Any idea what could be going wrong? What diagnostic stuff can I do to figure out what's happening? Is this failure mode typical of any sort of ailing computer part?

Computer specs:
Dual AMD Athlon MP 1800+ processors - these run a little hot, in the 60C range.
Asus a7m266-d motherboard
Allied AL-A400 ATX power supply, max 400w
Geforce4 ti4200 8x graphics card
768mb RAM [computer is in an awkward position to check precisely what kinds are in there]
Cheap Lite-on CD-ROM and DVD-ROM drives; the former is broken.
There are five hard drives; a 100GB WDC wd1000bb is the boot drive. There's a second internal drive - 120GB Maxtor. There are three external drives - a 300GB LaCie drive attached to a USB 1.0 port, along with a 200GB Western Digital drive and a 250GB LaCie drive attached to firewire ports.
The two monitors are a 17" KDS monitor and a 21" digital monitor; one attaches to the VGA port and the other to the DVI [with an adaptor.]
The OS is Windows XP Professional, SP 1, and I run regular checks for viruses, spyware, etc.

posted by ubersturm to computers & internet (8 comments total)

The fan on your GeForce4 is going out and the overheating has damaged the card to the point that it won't do the necessary graphics voodoo to get into windows? The GeForce4 ti4200 in my old computer did some weird stuff while the card was slowly dying from overheating, and when the dust clogged fan finally completely seized, burned up and wouldn't even run the display during boot-up.
posted by Derive the Hamiltonian of... at 3:12 PM on July 2, 2006

Video card overheating sounds like a good guess to me too.

Other suggestions.. Boot with a live CD, like knoppix or Bart's PE. Disconnect everything but the bare minimum components and test, borrow an old video card and test with that.

I've had an A7M266-D with the nichicon caps mentioned here: capacitor plague. A real piss off! It can be a real nasty problem to debug, because you can chase it for hours.. The symptoms keep changing.
posted by Chuckles at 3:42 PM on July 2, 2006

Video card was my first thought too, but the fact that I can boot up in safe mode [with both monitors running] left me less sure. Additionally, the video card's a good three or so years younger than most of the rest of the computer. Does nVidia have some sort of diagnostic program I could run in Safe Mode to check up on the video card [which is obviously not yet completely b0rked]?

Booting up with Knoppix sounds like a good way to check out the video card thing though; I'll try it as soon as I can get to a CD-burner. Capacitor plague sounds like a pain in the ass. I hope that's not it.
posted by ubersturm at 4:00 PM on July 2, 2006

I'd guess that your machine is overheating for some reason (mechanical problem with a fan, perhaps)... modern motherboards have temperature sensors, and can be configured to automatically shut the CPU off when it gets too hot. This happened when I first tried to use the last machine I bought, until I removed the packaging obstructing the fan inside the case. The automatic shutoff business can usually be configured in the BIOS, although its enabled for a good reason, of course. If you notice that the screens take longer to blank after you give the machine a few minutes to cool, as opposed to just rebooting immediately after blanking, then this is almost certainly your problem.
posted by gsteff at 4:34 PM on July 2, 2006

My video card recently screwed itself to the point where the pre-OS screen was totally scrambled, and it would go to a blank screen rather than Windows. However, I could still boot into safe mode as it uses very basic drivers. Card was only a year old as well - I'm pretty sure you have the same problem.
posted by Orange Goblin at 4:43 PM on July 2, 2006

To be clear, this could result in the machine shutting off while the fans stay on, creating the impression that only graphics died. If you can test whether sound still works after blanking, that would indicate whether this is happening.
posted by gsteff at 4:45 PM on July 2, 2006

I fried a video card once, and this is the kind of thing that happened. It was intermittent and hard to diagnose. The way I did it wasn't by obstructing the fan on the card; rather, the power cable to the card wasn't snapped on tight and it was arcing. So check your video card connections carefully, as well as making sure that the video card's fan is free of encumbrance and spins up properly.
posted by ikkyu2 at 7:47 PM on July 2, 2006

your video card is fried.
posted by sophist at 9:26 PM on July 2, 2006